fix(ci): Update Travis CI script so greenkeeper works with the lockfile

.travis.yml

@@ -19,6 +19,9 @@ addons:
 before_install:
   - nvm install node
   - npm install
+  - npm install -g greenkeeper-lockfile@1
+
+before_script: greenkeeper-lockfile-update
 
 script:
   - mvn package
@@ -28,6 +31,8 @@ script:
   - npm run lint-md
   - npm run lint-less
 
+after_script: greenkeeper-lockfile-upload
+
 cache:
   directories:
     - $HOME/.m2