It will compare code issues for merge request base and head and show
output in the merge request widget. Project must have codeclimate job added
to .gitlab-ci.yml according to https://docs.gitlab.com/ce/ci/examples/code_climate.html
and have finished pipeline for base and head commits of the merge
request
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>