Run metadata-json-lint test in lint job

If spec helper is available it will run the rake
task that is included in [1] otherwise it will
install metadata-json-lint and run it manually
like the other lint things does.

Only runs if the metadata.json file is available
so should not require any changes in modules if
something is wrong there.

[1] https://review.openstack.org/591605

Depends-On: https://review.openstack.org/591605
Change-Id: I60571e919e95327bf56a61bc33298a3810b942f7

.zuul.yaml

@@ -410,7 +410,6 @@
     irrelevant-files:
       - ^doc/.*$
       - ^etc/.*$
-      - ^metadata.json$
       - ^releasenotes/.*$
       - ^requirements.txt$
       - ^test-requirements.txt$

playbooks/run-lint-tests.yaml

@@ -22,11 +22,18 @@
             gem install bundler --no-rdoc --no-ri --verbose
             $GEM_HOME/bin/bundle install --without system_tests --retry 3
             $GEM_HOME/bin/bundle exec rake lint 2>&1
+            if [ -f metadata.json ]; then
+              $GEM_HOME/bin/bundle exec rake metadata_lint 2>&1
+            fi
           else
             gem install rake -n ./.bundled_gems/
             gem install puppet-lint
+            gem install metadata-json-lint -n ./.bundled_gems/ --no-ri --no-rdoc
             gem install puppetlabs_spec_helper
             ./.bundled_gems/rake lint 2>&1
+            if [ -f metadata.json ]; then
+              ./.bundled_gems/metadata-json-lint
+            fi
           fi
         chdir: '{{ ansible_user_dir }}/workspace'
       environment: '{{ zuul | zuul_legacy_vars }}'