fix 99: support string and map variants of container

pkg/model/workflow_test.go

@@ -70,3 +70,31 @@ jobs:
 	assert.Contains(t, workflow.On(), "push")
 	assert.Contains(t, workflow.On(), "pull_request")
 }
+
+func TestReadWorkflow_StringContainer(t *testing.T) {
+	yaml := `
+name: local-action-docker-url
+
+jobs:
+  test:
+    container: nginx:latest
+    runs-on: ubuntu-latest
+    steps:
+    - uses: ./actions/docker-url
+  test2:
+    container: 
+      image: nginx:latest
+      env:
+        foo: bar
+    runs-on: ubuntu-latest
+    steps:
+    - uses: ./actions/docker-url
+`
+
+	workflow, err := ReadWorkflow(strings.NewReader(yaml))
+	assert.NoError(t, err, "read workflow should succeed")
+	assert.Len(t, workflow.Jobs, 2)
+	assert.Contains(t, workflow.Jobs["test"].Container().Image, "nginx:latest")
+	assert.Contains(t, workflow.Jobs["test2"].Container().Image, "nginx:latest")
+	assert.Contains(t, workflow.Jobs["test2"].Container().Env["foo"], "bar")
+}