Reenable MySQL tests on all branches

To protect master from surprise failures, as long as we continue to support MySQL.

.gitlab-ci.yml

@@ -68,19 +68,6 @@ stages:
     - mysql:latest
     - redis:alpine
 
-.only-if-want-mysql: &only-if-want-mysql
-  only:
-    - /mysql/
-    - /-stable/
-    - master@gitlab-org/gitlab-ce
-    - master@gitlab-org/gitlab-ee
-    - master@gitlab/gitlabhq
-    - master@gitlab/gitlab-ee
-    - tags@gitlab-org/gitlab-ce
-    - tags@gitlab-org/gitlab-ee
-    - tags@gitlab/gitlabhq
-    - tags@gitlab/gitlab-ee
-
 # Skip all jobs except the ones that begin with 'docs/'.
 # Used for commits including ONLY documentation changes.
 # https://docs.gitlab.com/ce/development/writing_documentation.html#testing
@@ -124,7 +111,6 @@ stages:
 .rspec-metadata-mysql: &rspec-metadata-mysql
   <<: *rspec-metadata
   <<: *use-mysql
-  <<: *only-if-want-mysql
   <<: *except-docs
 
 .spinach-metadata: &spinach-metadata
@@ -156,7 +142,6 @@ stages:
 .spinach-metadata-mysql: &spinach-metadata-mysql
   <<: *spinach-metadata
   <<: *use-mysql
-  <<: *only-if-want-mysql
   <<: *except-docs
 
 .only-canonical-masters: &only-canonical-masters

doc/development/testing.md

@@ -529,10 +529,7 @@ slowest test files and try to improve them.
 
 ## CI setup
 
-- On CE, the test suite only runs against PostgreSQL by default. We additionally
-  run the suite against MySQL for tags, `master`, and any branch that includes
-  `mysql` in the name.
-- On EE, the test suite always runs both PostgreSQL and MySQL.
+- On CE and EE, the test suite runs both PostgreSQL and MySQL.
 - Rails logging to `log/test.log` is disabled by default in CI [for
   performance reasons][logging]. To override this setting, provide the
   `RAILS_ENABLE_TEST_LOG` environment variable.