manifest version use project.version (#119)

diff --git a/hugegraph-common/pom.xml b/hugegraph-common/pom.xml
index 862c3d7..cba4fef 100644
--- a/hugegraph-common/pom.xml
+++ b/hugegraph-common/pom.xml
@@ -239,7 +239,7 @@
                         <manifestEntries>
                             <!-- Must be on one line, otherwise the automatic
                                  upgrade script cannot replace the version number -->
-                            <Implementation-Version>${implementation.version}</Implementation-Version>
+                            <Implementation-Version>${project.version}</Implementation-Version>
                         </manifestEntries>
                     </archive>
                 </configuration>
diff --git a/hugegraph-rpc/pom.xml b/hugegraph-rpc/pom.xml
index 2a29065..ad5309d 100644
--- a/hugegraph-rpc/pom.xml
+++ b/hugegraph-rpc/pom.xml
@@ -132,7 +132,7 @@
                         <manifestEntries>
                             <!-- Must be on one line, otherwise the automatic
                                  upgrade script cannot replace the version number -->
-                            <Implementation-Version>${implementation.version}</Implementation-Version>
+                            <Implementation-Version>${project.version}</Implementation-Version>
                         </manifestEntries>
                     </archive>
                 </configuration>
diff --git a/pom.xml b/pom.xml
index ad7e3a4..7167a93 100644
--- a/pom.xml
+++ b/pom.xml
@@ -80,7 +80,6 @@
         <sun.xml.version>3.0.2</sun.xml.version>
         <checkstyle.plugin.version>3.1.2</checkstyle.plugin.version>
         <checkstyle.version>8.45</checkstyle.version>
-        <implementation.version>2.1.2.0</implementation.version>
     </properties>
 
     <modules>
@@ -149,7 +148,7 @@
                         <manifestEntries>
                             <!-- Must be on one line, otherwise the automatic
                                  upgrade script cannot replace the version number -->
-                            <Implementation-Version>${implementation.version}</Implementation-Version>
+                            <Implementation-Version>${project.version}</Implementation-Version>
                         </manifestEntries>
                     </archive>
                 </configuration>