Updated Travis environment to redirect 172.31.1.2 to 127.0.0.1

This allows test suites to use one IP address between both vagrant and
travis.
Removed option in travis test which triggered (irrelevant) warning)
Merge pull request #2 from tedivm/travis-ci-networking

Updated Travis environment to redirect 172.31.1.2 to 127.0.0.1