Trying to fix the travis issue
"Gem::RemoteFetcher::FetchError: Errno::ETIMEDOUT: Connection timed out - connect(2) for "rubygems.org" port 443"

Resources:
* https://gist.github.com/delano/845643
* https://github.com/elgalu/crafting_rails4_apps/blob/ecc0eed/.travis.yml#L13-L14
* http://blog.travis-ci.com/2013-05-20-network-timeouts-build-retries/
trying to avoid caching bug 'invalid encoding'