Merge pull request jsonwebtoken#162 from optikfluffel/travis-caching

Activate caching at Travis

Author: mike-casas

.travis.yml

@@ -7,3 +7,7 @@ before_script:
     - echo "  CheckHostIP no" >> ~/.ssh/config
     - npm install -g bower grunt-cli
     - bower install -f
+cache:
+  directories:
+  - node_modules
+  - vendor