Add test suite with PostgreSQL 10 to be run on a schedule

Also, move MySQL tests to run only on master branch, and on schedules.
Signed-off-by: Balasankar "Balu" C <balasankar@gitlab.com>

.gitlab-ci.yml

@@ -76,6 +76,11 @@ stages:
     - postgres:9.6
     - redis:alpine
 
+.use-pg-10: &use-pg-10
+  services:
+    - postgres:10.0
+    - redis:alpine
+
 .use-mysql: &use-mysql
   services:
     - mysql:5.7
@@ -97,6 +102,15 @@ stages:
     - /(^docs[\/-].*|.*-docs$)/
     - /(^qa[\/-].*|.*-qa$)/
 
+.only-schedules-master: &only-schedules-master
+  only:
+    - schedules@gitlab-org/gitlab-ce
+    - schedules@gitlab-org/gitlab-ee
+    - master@gitlab-org/gitlab-ce
+    - master@gitlab-org/gitlab-ee
+    - master@gitlab/gitlabhq
+    - master@gitlab/gitlab-ee
+
 # Jobs that only need to pull cache
 .dedicated-no-docs-pull-cache-job: &dedicated-no-docs-pull-cache-job
   <<: *dedicated-runner
@@ -172,6 +186,11 @@ stages:
   <<: *rspec-metadata
   <<: *use-pg
 
+.rspec-metadata-pg-10: &rspec-metadata-pg-10
+  <<: *rspec-metadata
+  <<: *use-pg-10
+  image: "dev.gitlab.org:5005/gitlab/gitlab-build-images:ruby-2.5.3-golang-1.11-git-2.18-chrome-71.0-node-10.x-yarn-1.12-postgresql-10-graphicsmagick-1.3.29"
+
 .rspec-metadata-mysql: &rspec-metadata-mysql
   <<: *rspec-metadata
   <<: *use-mysql
@@ -457,6 +476,8 @@ setup-test-env:
       - schedules@gitlab-org/gitlab-ce
       - schedules@gitlab-org/gitlab-ee
     kubernetes: active
+    variables:
+      - $REVIEW_APP_CLEANUP
   except:
     refs:
       - tags
@@ -525,8 +546,14 @@ rspec-pg:
   <<: *rspec-metadata-pg
   parallel: 50
 
+rspec-pg-10:
+  <<: *rspec-metadata-pg-10
+  <<: *only-schedules-master
+  parallel: 50
+
 rspec-mysql:
   <<: *rspec-metadata-mysql
+  <<: *only-schedules-master
   parallel: 50
 
 .rspec-quarantine: &rspec-quarantine