Enable RuboCop syntax linting in haml-lint
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/64753
c424ce52 - Ensure haml-lint checks Syntax
Also ensures we check Syntax with RuboCop, which is different.
f76669a1 - Fix haml-lint RuboCop error in admin/users/index
41e2be78 - Fix syntax errors in devise/sessions/_new_ldap
Edited by Robert Speicher