upgraded parent POM to latest 5.1

Author: hboutemy

pom.xml

@@ -22,7 +22,7 @@ limitations under the License.
   <parent>
     <groupId>org.codehaus.plexus</groupId>
     <artifactId>plexus</artifactId>
-    <version>4.0</version>
+    <version>5.1</version>
   </parent>
 
   <artifactId>plexus-utils</artifactId>
@@ -50,10 +50,6 @@ limitations under the License.
     </site>
   </distributionManagement>
 
-  <properties>
-    <javaVersion>6</javaVersion>
-  </properties>
-
   <dependencies>
       <dependency>
         <groupId>org.apache.maven.shared</groupId>
@@ -62,6 +58,7 @@ limitations under the License.
         <scope>test</scope>
       </dependency>
   </dependencies>
+
   <build>
     <pluginManagement>
       <plugins>
@@ -114,7 +111,6 @@ limitations under the License.
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-enforcer-plugin</artifactId>
-        <version>1.1.1</version>
         <executions>
           <execution>
             <id>enforce-java</id>
@@ -133,6 +129,7 @@ limitations under the License.
       </plugin>
     </plugins>
   </build>
+
   <profiles>
     <profile>
       <!-- See https://github.com/codehaus-plexus/plexus-utils/pull/27 -->