experimenting with travis install of all engines

part of #438

Author: bmuenzenmeyer

.travis.yml

@@ -11,11 +11,15 @@ before_install:
 
 before_script:
   - npm install -g grunt-cli
+  - npm install patternengine-node-underscore
+  - npm install patternengine-node-handlebars
+  - npm install patternengine-node-twig
 
 branches:
   only:
     - master
     - dev
+    - 438-runAllTestsTravis
 
 notifications:
   webhooks: