resolve travis-ci.org / travis.com distinction

[breezykermo]

It seems that Travis recently moved all of its support to .com (it used to have a distinction between .com for paid, and .org for free/OSS).

The CI infra for this repo is a little funny at the moment, in the sense that only @breezykermo seems to be able to encrypt the .env file to create a passing build. (We had thought that any maintainer could do so.)

Could this be fixed by moving to .com? Is encrypting the .env file locally a non-idiomatic or otherwise frail way to get around the fact that we need secret credentials on the Travis server in order to run all the tests?