Remove plugin versions from pom.xml

They are inherited via the parent.

Author: bernd

pom.xml

@@ -128,7 +128,6 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
-                <version>2.4.3</version>
                 <configuration>
                     <minimizeJar>false</minimizeJar>
                 </configuration>
@@ -179,7 +178,6 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-release-plugin</artifactId>
-                <version>2.5.3</version>
                 <configuration>
                     <autoVersionSubmodules>true</autoVersionSubmodules>
                     <mavenExecutorId>forked-path</mavenExecutorId>
@@ -247,7 +245,6 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>2.19.1</version>
                 <configuration>
                     <systemProperties>
                         <property>