Finish travis/bintray stuff

[jackmcbarn]

• [ ] Make the Bintray upload not error out for tags or game branches https://travis-ci.org/CensoredUsername/unrpyc/builds/190078228
• [ ] Add a separate package for releases, for above
• [ ] Add the files to the download list travis-ci/dpl#565
• [ ] Link to Bintray from README.md
• [x] Add a test .rpyc file and make sure it becomes its matching .rpy file
• [ ] Maybe make it test actually round-tripping with Ren'Py instead of putting rpyc files in git
• [ ] Some sort of test for dumping

[CensoredUsername]

This issue has been outdated for several years as we moved to github actions.