update nodejs dependency version

.travis.yml

@@ -28,7 +28,7 @@ services:
   - redis
 
 before_install:
-  - nvm install 0.12.0
+  - nvm install stable
   - phpenv config-rm xdebug.ini
   - composer self-update --no-progress --no-interaction
   - sudo apt-get purge elasticsearch
@@ -59,7 +59,6 @@ before_script:
   - "./bin/developer phraseanet:generate-js-fixtures"
 
 script:
-  - "./node_modules/.bin/gulp test"
   - |
     echo "$TEST_SUITE";
     case "$TEST_SUITE" in