npm caching by default

Travis CI now caches the npm packages you've used during build time by default so that they're used in subsequent builds, effectively speeding up your builds.

Depending on the repository's structure, it caches either $HOME/.npm or node_modules.

To disable the default npm caching, please add the following to your .travis.yml file:

cache:
  npm: false

For more details, please check out our Caching Dependencies docs.