[GR-17457] GitHub Actions: add specs on CRuby 2.7 and jt test fast

PullRequest: truffleruby/2222

Author: eregon

.github/workflows/ci.yml

@@ -4,7 +4,7 @@ name: CI
 on: [push, pull_request]
 jobs:
   lint:
-    name: Lint
+    name: jt lint + jt test fast
     runs-on: ubuntu-20.04
     steps:
     - name: Clone TruffleRuby
@@ -34,19 +34,23 @@ jobs:
 
     - name: Install RuboCop
       run: gem install --no-document rubocop:0.66.0
-    - run: tool/jt.rb lint
+    - name: jt lint
+      run: tool/jt.rb lint
+
+    - name: jt test fast
+      run: tool/jt.rb test fast
 
   mri_specs:
     name: Run ruby/spec on CRuby ${{ matrix.ruby }}
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.5, 2.6]
+        ruby: [2.5, 2.6, 2.7]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler: none
-      - run: CHECK_LEAKS=true tool/jt.rb -u ruby mspec -fdot spec/ruby
+      - run: CHECK_LEAKS=true tool/jt.rb -u ruby mspec -fdot --timeout 30 spec/ruby