Pick up spotbugs-maven-plugin version from parent

pom.xml

@@ -557,8 +557,6 @@ under the License.
     <commons.jira.pid>12310484</commons.jira.pid>
     <!-- The RC version used in the staging repository URL. -->
     <commons.rc.version>RC2</commons.rc.version>
-    <spotbugs.plugin.version>4.7.2.1</spotbugs.plugin.version>
-    <spotbugs.impl.version>4.7.3</spotbugs.impl.version>    
     <skipSurefireReport>true</skipSurefireReport>
     <!-- Allow default test run order to be changed -->
     <failsafe.runorder>filesystem</failsafe.runorder>