Run Rubocop-git including commit itself

Author: blelump

.travis.yml

@@ -9,7 +9,7 @@ script:
     for sha1 in $(git log --format=format:%H ${TRAVIS_COMMIT_RANGE}); do
       echo $sha1;
       git log --format=%B -n 1 $sha1;
-      bundle exec rubocop-git $sha1;
+      bundle exec rubocop-git "${sha1}~1";
       if (( $? != 0 )); then rc=1; fi;
       echo -e "\n\n\n";
     done;