Add more steps context support (#887)

* feat: add more steps context support

- Add step outcome
- Remove step success in favour of conclusion

* feat: add conclusion and outcome steps context tests

Add corresponding tests and extend pkg/runner/expression.go vmSteps() to
handle steps context conclusion and outcome iota as strings.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

pkg/runner/testdata/steps-context/conclusion/push.yml

@@ -0,0 +1,14 @@
+name: conclusion
+on: push
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - id: first
+        run: exit 0
+      - id: second
+        continue-on-error: true
+        run: exit 1
+      - run: echo '${{ steps.first.conclusion }}' | grep 'success'
+      - run: echo '${{ steps.second.conclusion }}' | grep 'success'

pkg/runner/testdata/steps-context/outcome/push.yml

@@ -0,0 +1,14 @@
+name: outcome
+on: push
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - id: first
+        run: exit 0
+      - id: second
+        continue-on-error: true
+        run: exit 1
+      - run: echo '${{ steps.first.outcome }}' | grep 'success'
+      - run: echo '${{ steps.second.outcome }}' | grep 'failure'