[maven-release-plugin] prepare release nemo-project-0.4
diff --git a/client/pom.xml b/client/pom.xml
index 2de9827..18257c8 100644
--- a/client/pom.xml
+++ b/client/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-project</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/common/pom.xml b/common/pom.xml
index a0ab9ba..d1c5ea7 100644
--- a/common/pom.xml
+++ b/common/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-project</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/compiler/backend/pom.xml b/compiler/backend/pom.xml
index e461d4e..843dec3 100644
--- a/compiler/backend/pom.xml
+++ b/compiler/backend/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/compiler/frontend/beam/pom.xml b/compiler/frontend/beam/pom.xml
index b5501d1..6ff1617 100644
--- a/compiler/frontend/beam/pom.xml
+++ b/compiler/frontend/beam/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../../</relativePath>
   </parent>
 
diff --git a/compiler/frontend/spark/pom.xml b/compiler/frontend/spark/pom.xml
index f135fd8..5b1331e 100644
--- a/compiler/frontend/spark/pom.xml
+++ b/compiler/frontend/spark/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../../</relativePath>
   </parent>
 
diff --git a/compiler/optimizer/pom.xml b/compiler/optimizer/pom.xml
index 49a546d..991f64e 100644
--- a/compiler/optimizer/pom.xml
+++ b/compiler/optimizer/pom.xml
@@ -35,7 +35,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/compiler/pom.xml b/compiler/pom.xml
index 6762fbe..c871b91 100644
--- a/compiler/pom.xml
+++ b/compiler/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <artifactId>nemo-project</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
   <modelVersion>4.0.0</modelVersion>
diff --git a/compiler/test/pom.xml b/compiler/test/pom.xml
index 4b0b1ec..8101122 100644
--- a/compiler/test/pom.xml
+++ b/compiler/test/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-compiler</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/conf/pom.xml b/conf/pom.xml
index fc7ada1..bc38a18 100644
--- a/conf/pom.xml
+++ b/conf/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-project</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/examples/beam/pom.xml b/examples/beam/pom.xml
index 65651a3..056795a 100644
--- a/examples/beam/pom.xml
+++ b/examples/beam/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-examples</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/examples/nexmark/pom.xml b/examples/nexmark/pom.xml
index 71672bf..9f6b01e 100644
--- a/examples/nexmark/pom.xml
+++ b/examples/nexmark/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <artifactId>nemo-examples</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
 
diff --git a/examples/pom.xml b/examples/pom.xml
index 5f58afc..a000bbf 100644
--- a/examples/pom.xml
+++ b/examples/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <artifactId>nemo-project</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
 
diff --git a/examples/spark/pom.xml b/examples/spark/pom.xml
index 7a7878c..eace6f4 100644
--- a/examples/spark/pom.xml
+++ b/examples/spark/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <artifactId>nemo-examples</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/pom.xml b/pom.xml
index ac09b14..222eee5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -28,7 +28,7 @@
 
   <groupId>org.apache.nemo</groupId>
   <artifactId>nemo-project</artifactId>
-  <version>0.4-SNAPSHOT</version>
+  <version>0.4</version>
   <packaging>pom</packaging>
   <name>Nemo Project</name>
 
@@ -36,7 +36,7 @@
     <connection>scm:git:https://gitbox.apache.org/repos/asf/incubator-nemo.git</connection>
     <developerConnection>scm:git:https://gitbox.apache.org/repos/asf/incubator-nemo.git</developerConnection>
     <url>https://github.com/apache/incubator-nemo/tree/${project.scm.tag}</url>
-    <tag>master</tag>
+    <tag>nemo-project-0.4</tag>
   </scm>
 
   <properties>
diff --git a/runtime/common/pom.xml b/runtime/common/pom.xml
index 75cfa14..7417279 100644
--- a/runtime/common/pom.xml
+++ b/runtime/common/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/runtime/driver/pom.xml b/runtime/driver/pom.xml
index 51c8f94..9c9c230 100644
--- a/runtime/driver/pom.xml
+++ b/runtime/driver/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
   <modelVersion>4.0.0</modelVersion>
diff --git a/runtime/executor/pom.xml b/runtime/executor/pom.xml
index 1f95aa1..b1814c5 100644
--- a/runtime/executor/pom.xml
+++ b/runtime/executor/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/runtime/master/pom.xml b/runtime/master/pom.xml
index f015abc..85019e8 100644
--- a/runtime/master/pom.xml
+++ b/runtime/master/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
 
diff --git a/runtime/pom.xml b/runtime/pom.xml
index 71a9b45..842247e 100644
--- a/runtime/pom.xml
+++ b/runtime/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <artifactId>nemo-project</artifactId>
     <groupId>org.apache.nemo</groupId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>
   <modelVersion>4.0.0</modelVersion>
diff --git a/runtime/test/pom.xml b/runtime/test/pom.xml
index 91342f3..0d9c61a 100644
--- a/runtime/test/pom.xml
+++ b/runtime/test/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.nemo</groupId>
     <artifactId>nemo-runtime</artifactId>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
     <relativePath>../</relativePath>
   </parent>