Enable Travis CI to run on Pull Requests

[and-semakin]

As far as I can see, the repo contains .travis.yml file, but Travis isn't triggered when somebody creates/pushes a pull request. I suspect that something is wrong in Travis settings itself.

Troubleshooting guide: https://docs.travis-ci.com/user/common-build-problems/#i-pushed-a-commit-and-cant-find-its-corresponding-build

[sybrenstuvel]

On https://travis-ci.org/github/sybrenstuvel/python-rsa it states:

Travis CI - Test and Deploy Your Code with Confidence is in read-only mode. The historical data can be downloaded to external file storage.

The .org website has been discontinued. I've tried setting things up on the .com website, but there it lists pretty much all my Github repositories except python-rsa. I've contacted TravisCI about this, hope to get an answer soon.