[Nemo-439] Upgrade current working version to 0.3-SNAPSHOT (#290)

JIRA: [NEMO-439: Upgrade current working version to 0.3-SNAPSHOT](https://issues.apache.org/jira/projects/NEMO/issues/NEMO-439)

**Major changes:**
- Upgrades the current working version to 0.3-SNAPSHOT as v0.2 has been released.

**Minor changes to note:**
- N/A

**Tests for the changes:**
- N/A

**Other comments:**
- v0.2 has been released.
diff --git a/client/pom.xml b/client/pom.xml
index a2eba1f..e869a88 100644
--- a/client/pom.xml
+++ b/client/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-project</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/common/pom.xml b/common/pom.xml
index 65888f8..87de322 100644
--- a/common/pom.xml
+++ b/common/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-project</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/compiler/backend/pom.xml b/compiler/backend/pom.xml
index 625a313..4e2ead7 100644
--- a/compiler/backend/pom.xml
+++ b/compiler/backend/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/compiler/frontend/beam/pom.xml b/compiler/frontend/beam/pom.xml
index 7a455d3..1c25117 100644
--- a/compiler/frontend/beam/pom.xml
+++ b/compiler/frontend/beam/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../../</relativePath>
   </parent>
 
diff --git a/compiler/frontend/spark/pom.xml b/compiler/frontend/spark/pom.xml
index 843600b..8938b53 100644
--- a/compiler/frontend/spark/pom.xml
+++ b/compiler/frontend/spark/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../../</relativePath>
   </parent>
 
diff --git a/compiler/optimizer/pom.xml b/compiler/optimizer/pom.xml
index bda16bc..9b9c4c1 100644
--- a/compiler/optimizer/pom.xml
+++ b/compiler/optimizer/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/compiler/pom.xml b/compiler/pom.xml
index ad85ef5..aaf93cd 100644
--- a/compiler/pom.xml
+++ b/compiler/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <artifactId>nemo-project</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
   <modelVersion>4.0.0</modelVersion>
diff --git a/compiler/test/pom.xml b/compiler/test/pom.xml
index 69f3747..12f6569 100644
--- a/compiler/test/pom.xml
+++ b/compiler/test/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/conf/pom.xml b/conf/pom.xml
index c570d6d..e25be3c 100644
--- a/conf/pom.xml
+++ b/conf/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-project</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/examples/beam/pom.xml b/examples/beam/pom.xml
index 8ba7c8e..75b9785 100644
--- a/examples/beam/pom.xml
+++ b/examples/beam/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-examples</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/examples/nexmark/pom.xml b/examples/nexmark/pom.xml
index 9fb0a08..7ea5cce 100644
--- a/examples/nexmark/pom.xml
+++ b/examples/nexmark/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <artifactId>nemo-examples</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
 
diff --git a/examples/pom.xml b/examples/pom.xml
index f0c478b..8c1bb46 100644
--- a/examples/pom.xml
+++ b/examples/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <artifactId>nemo-project</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
 
diff --git a/examples/spark/pom.xml b/examples/spark/pom.xml
index d9fcd57..7cf23f0 100644
--- a/examples/spark/pom.xml
+++ b/examples/spark/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <artifactId>nemo-examples</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/pom.xml b/pom.xml
index 783565b..31698e2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -29,7 +29,7 @@
 
   <groupId>org.apache.nemo</groupId>
   <artifactId>nemo-project</artifactId>
-  <version>0.2-SNAPSHOT</version>
+  <version>0.3-SNAPSHOT</version>
   <packaging>pom</packaging>
   <name>Nemo Project</name>
 
diff --git a/runtime/common/pom.xml b/runtime/common/pom.xml
index 9912491..c4ebf4d 100644
--- a/runtime/common/pom.xml
+++ b/runtime/common/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/runtime/driver/pom.xml b/runtime/driver/pom.xml
index 6735939..db8fa1d 100644
--- a/runtime/driver/pom.xml
+++ b/runtime/driver/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
   <modelVersion>4.0.0</modelVersion>
diff --git a/runtime/executor/pom.xml b/runtime/executor/pom.xml
index de3ee44..bec9c04 100644
--- a/runtime/executor/pom.xml
+++ b/runtime/executor/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
@@ -62,7 +62,7 @@
     <dependency>
       <groupId>org.apache.nemo</groupId>
       <artifactId>nemo-runtime-master</artifactId>
-      <version>0.2-SNAPSHOT</version>
+      <version>0.3-SNAPSHOT</version>
       <scope>test</scope>
     </dependency>
     <dependency>
diff --git a/runtime/master/pom.xml b/runtime/master/pom.xml
index af59787..82c1ce4 100644
--- a/runtime/master/pom.xml
+++ b/runtime/master/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/runtime/pom.xml b/runtime/pom.xml
index b6cd38e..063f1d0 100644
--- a/runtime/pom.xml
+++ b/runtime/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <artifactId>nemo-project</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>
   <modelVersion>4.0.0</modelVersion>
diff --git a/runtime/test/pom.xml b/runtime/test/pom.xml
index 012b5cc..6fd24bf 100644
--- a/runtime/test/pom.xml
+++ b/runtime/test/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.2-SNAPSHOT</version>
+    <version>0.3-SNAPSHOT</version>
     <relativePath>../</relativePath>
   </parent>