Enable yaml lint

This will enable yaml lint again as it was
disabled because not working properly before

Fix an yaml lint error

tekton/get-version.yaml

@@ -14,7 +14,8 @@ spec:
     script: |
       git status && git fetch -p --all
   - name: get-versions
-    image: goreleaser/goreleaser # because it has git
+    # because it has git
+    image: goreleaser/goreleaser
     workingDir: /workspace/source
     script: |
       echo -n $(git tag --points-at HEAD) > /tekton/results/version

test/presubmit-tests.sh

@@ -91,9 +91,7 @@ function post_build_tests() {
     test_golden_has_been_generated
     test_documentation_has_been_generated
     check_go_lint
-    # Skipping yaml lint because of some issue in CI
-    # https://github.com/tektoncd/plumbing/issues/307
-    # check_yaml_lint
+    check_yaml_lint
 }
 
 # We use the default build, unit and integration test runners.