Bump version to 3.1.0-SNAPSHOT for the upcoming changes

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1799179 13f79535-47bb-0310-9956-ffa450edef68

Author: michael-o

maven-assembly-plugin/pom.xml

@@ -30,7 +30,7 @@ under the License.
   </parent>
 
   <artifactId>maven-assembly-plugin</artifactId>
-  <version>3.0.1-SNAPSHOT</version>
+  <version>3.1.0-SNAPSHOT</version>
   <packaging>maven-plugin</packaging>
 
   <name>Apache Maven Assembly Plugin</name>