Update maven plugins

Change-Id: Idda470ff355cc1ab559c3c64189e8b1df173dc55
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
diff --git a/pom.xml b/pom.xml
index f924043..f506656 100644
--- a/pom.xml
+++ b/pom.xml
@@ -216,7 +216,7 @@
 
         <plugin>
           <artifactId>maven-compiler-plugin</artifactId>
-          <version>2.5.1</version>
+          <version>3.1</version>
         </plugin>
 
         <plugin>
@@ -227,7 +227,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-shade-plugin</artifactId>
-          <version>1.7.1</version>
+          <version>2.1</version>
         </plugin>
 
         <plugin>
@@ -239,31 +239,31 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-dependency-plugin</artifactId>
-          <version>2.5</version>
+          <version>2.8</version>
         </plugin>
 
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-source-plugin</artifactId>
-          <version>2.2</version>
+          <version>2.2.1</version>
         </plugin>
 
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-javadoc-plugin</artifactId>
-          <version>2.8.1</version>
+          <version>2.9.1</version>
         </plugin>
 
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-surefire-plugin</artifactId>
-          <version>2.12.2</version>
+          <version>2.16</version>
         </plugin>
 
         <plugin>
           <groupId>org.codehaus.mojo</groupId>
           <artifactId>build-helper-maven-plugin</artifactId>
-          <version>1.7</version>
+          <version>1.8</version>
         </plugin>
 
         <plugin>
@@ -286,7 +286,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-pmd-plugin</artifactId>
-          <version>2.7.1</version>
+          <version>3.0.1</version>
           <configuration>
             <sourceEncoding>utf-8</sourceEncoding>
             <minimumTokens>100</minimumTokens>