Added a autowired CommentService in the AbstractRepoIntegrationTest.java

Hello, 
We need to test the commentService so I have added that to the AbstractRepoIT. 
NB.
This little trivial addition could not be tested local due to depencies issues,
[ERROR] Failed to execute goal on project alfresco-test-repo: Could not resolve dependencies for project org.redpill-linpro.alfresco:alfresco-test-repo:jar:1.0.3:
 Could not find artifact org.alfresco:alfresco-repository:jar:4.2.2 in redpill-linpro (http://maven.redpill-linpro.com/nexus/content/groups/public) -