chore: merge license & checkstyle & ci

1. root pom.xml, license, checkstyle, ci,
diff --git a/.github/ISSUE_TEMPLATE/bug_report.yml b/.github/ISSUE_TEMPLATE/bug_report.yml
index 780d51e..8445d0a 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/bug_report.yml
@@ -11,7 +11,7 @@
         ### Note (特别注意) : 
 
         > 1. 请先**搜索**现有的[Server-Issues](https://github.com/hugegraph/hugegraph/issues) 与
-        [Common-Issues](https://github.com/hugegraph/hugegraph-common/issues) 中没有与您相同
+        [Commons-Issues](https://github.com/hugegraph/hugegraph-commons/issues) 中没有与您相同
         / 相关的问题 (请勿重复提交)
 
         > 2. 我们需要尽可能**详细**的信息来**复现**问题, 越详细的信息 (包括**日志 / 截图 / 配置**等)
@@ -35,7 +35,7 @@
     attributes:
       label: Before submit
       options:
-        - label: 我已经确认现有的 [Server-Issues](https://github.com/hugegraph/hugegraph/issues) 与 [Common-Issues](https://github.com/hugegraph/hugegraph-common/issues) 中没有相同 / 重复问题
+        - label: 我已经确认现有的 [Server-Issues](https://github.com/hugegraph/hugegraph/issues) 与 [Commons-Issues](https://github.com/hugegraph/hugegraph-commons/issues) 中没有相同 / 重复问题
           required: true
 
   - type: textarea
diff --git a/.github/ISSUE_TEMPLATE/question_ask.yml b/.github/ISSUE_TEMPLATE/question_ask.yml
index 6a57883..9724e66 100644
--- a/.github/ISSUE_TEMPLATE/question_ask.yml
+++ b/.github/ISSUE_TEMPLATE/question_ask.yml
@@ -9,7 +9,7 @@
         ### Note (特别注意) : 
 
         > 1. 请先**搜索**现有的[Server-Issues](https://github.com/hugegraph/hugegraph/issues) 与
-        [Common-Issues](https://github.com/hugegraph/hugegraph-common/issues) 中没有与您相同
+        [Commons-Issues](https://github.com/hugegraph/hugegraph-commons/issues) 中没有与您相同
         / 相关的问题 (请勿重复提交)
 
         > 2. 我们需要尽可能**详细**的信息来**复现**问题, 越详细的信息 (包括**日志 / 截图 / 配置**等)
@@ -33,7 +33,7 @@
     attributes:
       label: Before submit
       options:
-        - label: 我已经确认现有的 [Server-Issues](https://github.com/hugegraph/hugegraph/issues) 与 [Common-Issues](https://github.com/hugegraph/hugegraph-common/issues) 中没有相同 / 重复问题
+        - label: 我已经确认现有的 [Server-Issues](https://github.com/hugegraph/hugegraph/issues) 与 [Commons-Issues](https://github.com/hugegraph/hugegraph-commons/issues) 中没有相同 / 重复问题
           required: true
 
   - type: textarea
diff --git a/.travis.yml b/.github/outdated/.travis.yml
similarity index 100%
rename from .travis.yml
rename to .github/outdated/.travis.yml
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5dda168..a09093a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,4 +1,4 @@
-name: hugegraph-common ci
+name: hugegraph-commons ci
 
 on:
   push:
diff --git a/.github/workflows/stale.yml b/.github/workflows/stale.yml
index 1813bd3..5829cb6 100644
--- a/.github/workflows/stale.yml
+++ b/.github/workflows/stale.yml
@@ -20,17 +20,19 @@
         stale-pr-message: 'Due to the lack of activity, the current pr is marked as stale and will be closed after 180 days, any update will remove the stale label'
         stale-issue-label: 'inactive'
         stale-pr-label: 'inactive'
-        exempt-issue-labels: 'feature,bug,enhancement,improvement,wontfix,todo'
+        exempt-issue-labels: 'feature,bug,enhancement,improvement,wontfix,todo,help wanted'
+        exempt-pr-labels: 'feature,bug,enhancement,improvement,wontfix,todo,help wanted'
+        exempt-all-milestones: true
 
         days-before-issue-stale: 15
         days-before-issue-close: 20
         days-before-pr-stale: 30
         days-before-pr-close: 180
         operations-per-run: 10
-        start-date: '2018-12-01T00:00:00Z'
+        start-date: '2018-10-01T00:00:00Z'
 
         exempt-all-assignees: true
         remove-stale-when-updated: true
         exempt-all-pr-milestones: true
         delete-branch: false
-        enable-statistics: true
+        enable-statistics: true
\ No newline at end of file
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..e06d208
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,202 @@
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diff --git a/checkstyle.xml b/checkstyle.xml
new file mode 100644
index 0000000..9373a70
--- /dev/null
+++ b/checkstyle.xml
@@ -0,0 +1,89 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE module PUBLIC
+        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+        "https://checkstyle.org/dtds/configuration_1_3.dtd">
+<!-- 参考:https://checkstyle.sourceforge.io/checks.html -->
+<module name="Checker">
+    <!--检查不通过时被判定的违规级别,必须修复后才能使build通过-->
+    <property name="severity" value="error"/>
+    <!--对java文件做检查-->
+    <property name="fileExtensions" value="java"/>
+    <!--对UTF-8编码的文件做检查-->
+    <property name="charset" value="UTF-8"/>
+    <!--文件中不允许包含制表符-->
+    <module name="FileTabCharacter">
+        <property name="eachLine" value="true"/>
+    </module>
+
+    <!--检查java源文件并定义一些适用于检查此类文件的一些属性-->
+    <module name="TreeWalker">
+        <!--检查行长度-->
+        <module name="LineLength">
+            <property name="max" value="80"/>
+            <!--可以忽略的行-->
+            <property name="ignorePattern"
+                      value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+        </module>
+        <!--检查没有import语句使用*号-->
+        <module name="AvoidStarImport"/>
+        <!--检查是否存在多余的import语句,比如重复的,java自带的包,相同包下的其他类-->
+        <module name="RedundantImport"/>
+        <!--检查是否存在没有使用的import语句-->
+        <module name="UnusedImports"/>
+        <!--检查包名称是否遵守命名规约-->
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+        </module>
+        <!--检查局部变量的名称是否遵守命名规约-->
+        <module name="LocalVariableName">
+            <property name="format" value="^[a-z][a-zA-Z0-9_]*$"/>
+        </module>
+        <!--检查成员变量(非静态字段)的名称是否遵守命名规约-->
+        <module name="MemberName">
+            <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
+        </module>
+        <!--检查方法名称是否遵守命名规约-->
+        <module name="MethodName">
+            <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
+        </module>
+        <!--检查参数名称是否遵守命名规约-->
+        <module name="ParameterName">
+            <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
+        </module>
+        <!--检查常量(用static final修饰的字段)的名称是否遵守命名规约-->
+        <module name="ConstantName">
+            <property name="format" value="^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$"/>
+        </module>
+        <!--检查数组是否属于java风格,方括号放在类型后面,而不是变量后面,比如:int[] nums(合法),int nums[](不合法)-->
+        <module name="ArrayTypeStyle">
+            <property name="javaStyle" value="true"/>
+        </module>
+        <!--long类型的字面量如果要以"L"结尾,必须是大写的"L",而非小写的"l"-->
+        <module name="UpperEll"/>
+        <!--代码换行时,运算符必须在当前行的末尾,比如:+、&&、?、: 等-->
+        <module name="OperatorWrap">
+            <property name="option" value="eol"/>
+        </module>
+        <!--检查指定标记的周围是否有空格,比如:if、for、while、synchoronized 等-->
+        <module name="WhitespaceAround"/>
+        <!--左圆括号之后和右圆括号之前是否需要有一个空格,不需要-->
+        <module name="ParenPad"/>
+        <!--检查修饰符是否符合Java建议,顺序是:public、protected、private、abstract、default、static、final、transient、volatile、synchronized、native、strictfp-->
+        <module name="ModifierOrder"/>
+        <!--检查代码块的左花括号的放置位置,必须在当前行的末尾-->
+        <module name="LeftCurly">
+            <property name="option" value="eol"/>
+            <property name="ignoreEnums" value="false"/>
+        </module>
+        <!--代码中不允许有空语句,也就是单独的;符号-->
+        <module name="EmptyStatement"/>
+        <!--覆盖equals()方法的类必须也覆盖了hashCode()方法-->
+        <module name="EqualsHashCode"/>
+        <!--switch语句必须含有default子句-->
+        <module name="MissingSwitchDefault"/>
+        <!--switch语句的default必须放在所有的case分支之后-->
+        <module name="DefaultComesLast"/>
+        <!--覆盖clone()方法时调用了super.clone()方法-->
+        <module name="SuperClone"/>
+    </module>
+</module>
diff --git a/hugegraph-common/BCLOUD b/hugegraph-common/BCLOUD
deleted file mode 100644
index df3f342..0000000
--- a/hugegraph-common/BCLOUD
+++ /dev/null
@@ -1 +0,0 @@
-BUILD_SUBMITTER -x -u ./ -e CENTOS6U3 -m baidu/xbu-data/hugegraph-common -c "export MAVEN_HOME=/home/scmtools/buildkit/maven/apache-maven-3.3.9/ && export JAVA_HOME=/home/scmtools/buildkit/java/jdk1.8.0_25/ && export PATH=$JAVA_HOME/bin:$MAVEN_HOME/bin:$PATH && cd baidu/xbu-data/hugegraph-common && mkdir output && sh build.sh" -o output
\ No newline at end of file