revert: gem install
revert: gem install

- since the other coverage report didn't cause any issue to generate. 
- this might be wrong direction to check. 
- reverting to the no-coverage workaround.
couchbase/couchbase-lite-ios,couchbase/couchbase-lite-ios,couchbase/couchbase-lite-ios,couchbase/couchbase-lite-ios,couchbase/couchbase-lite-ios,couchbase/couchbase-lite-ios