title: Travis CI testing branches with corresponding set of environment variables
body: <p>I have a project that I'm trying to automate tests using Travis CI. I have a dev branch and a test branch, and they have different environment variables. For example, on the dev branch, I need to connect to a different API than the test branch, specified by an environment variable. So, when I run the build on the dev branch on Travis, how do I set it up so that it only tests with the dev set of environment variables, and likewise for build on test branch? </p>