Rework the build pipeline.

+ Separate out lint to its own stage.
+ Switch off of -stretch.
+ Switch 2.7 to final.
+ Default rake task is now just test.

Signed-off-by: Ryan Davis <zenspider@chef.io>

.expeditor/buildkite/verify.sh

@@ -20,5 +20,4 @@ echo "--- push bundle cache"
 push_bundle
 
 echo "+++ bundle exec rake"
-bundle exec rake
-
+bundle exec rake ${RAKE_TASK:-}

.expeditor/verify.pipeline.yml

@@ -1,37 +1,45 @@
 ---
 steps:
 
+- label: lint-ruby-2.6
+  command:
+    - RAKE_TASK=lint /workdir/.expeditor/buildkite/verify.sh
+  expeditor:
+    executor:
+      docker:
+        image: ruby:2.6
+
 - label: run-tests-ruby-2.4
   command:
     - /workdir/.expeditor/buildkite/verify.sh
   expeditor:
     executor:
       docker:
-        image: ruby:2.4-stretch
+        image: ruby:2.4
 
 - label: run-tests-ruby-2.5
   command:
     - /workdir/.expeditor/buildkite/verify.sh
   expeditor:
     executor:
       docker:
-        image: ruby:2.5-stretch
+        image: ruby:2.5
 
 - label: run-tests-ruby-2.6
   command:
     - /workdir/.expeditor/buildkite/verify.sh
   expeditor:
     executor:
       docker:
-        image: ruby:2.6-stretch
+        image: ruby:2.6
 
 - label: run-tests-ruby-2.7
   command:
     - /workdir/.expeditor/buildkite/verify.sh
   expeditor:
     executor:
       docker:
-        image: ruby:2.7-rc
+        image: ruby:2.7
 
 - label: run-tests-ruby-2.6-windows
   command:

Rakefile

@@ -14,7 +14,7 @@ RuboCop::RakeTask.new(:lint) do |task|
 end
 
 # run tests
-task default: %i{test lint}
+task default: %i{test}
 
 Rake::TestTask.new do |t|
   t.libs << "test"