Ensure that RAILS_ENV and RACK_ENV are not set
Ensure that RAILS_ENV and RACK_ENV are not set

On Travis CI, these env vars automatically exist, which means we end up
running stuff in the test env by default, rather than the development
env.

y-yagi/spring,grosser/spring,ypresto/spring,slobodankovacevic/spring,pigoz/spring,maclover7/spring,smathy/spring,mariusbutuc/spring,universsky/spring-1,rails/spring