Make travis read the node version from the .nvmrc file

See https://docs.travis-ci.com/user/languages/javascript-with-nodejs/#Specifying-Node.js-versions-using-.nvmrc

services/clsi/.travis.yml

@@ -1,8 +1,5 @@
 language: node_js
 
-node_js:
-    - "0.10"
-
 before_install:
     - npm install -g grunt-cli