feat(): multiple stages on pstage command

Author: sbonacho

lib/stepper.js

@@ -80,7 +80,7 @@ const stepper = function() {
       logger.trace('#green', 'stepper', 'running', '#cyan', config.stages[n], '(', n, 'of', config.stages.length, ')');
       _setWorkingDir();
 
-      if (!step.params.pstage || config.stages[n] === step.params.pstage) {
+      if (!step.params.pstage || step.params.pstage.indexOf(config.stages[n]) >= 0) {
 
         step._doPlugins(config.stages[n])
           .then((result) => {