Changed scope of Java deps to "test".

This is per: https://github.com/google/protobuf/issues/2019

java/core/pom.xml

@@ -22,14 +22,17 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
+      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.easymock</groupId>
       <artifactId>easymock</artifactId>
+      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.easymock</groupId>
       <artifactId>easymockclassextension</artifactId>
+      <scope>test</scope>
     </dependency>
   </dependencies>