fix #127 - force eval as a boolean (#131)

pkg/runner/testdata/commands/push.yml

@@ -11,11 +11,18 @@ jobs:
         run: echo $foo | grep bar
 
       - name: TEST set-output
+        id: set_output
         run: echo "::set-output name=zoo::zar"
 
       #- run: echo "::add-path::/zip"
       #- run: echo $PATH | grep /zip
 
+      - name: TEST conditional
+        if: steps.set_output.outputs.zoo
+        run: echo "::set-env name=cond_env::foo"
+      - name: TEST conditional (cont.)
+        run: echo $cond_env | grep foo
+
       - name: TEST debug, warning, error
         run: |
           echo "::debug file=app.js,line=100,col=20::Hello debug!"