custom travis api URL

[alok760]

I'm submitting a ... (check one with "x")

• [ ] bug report
• [x] feature request
• [ ] support request => Please do not submit support requests here, instead ask your query in out Gitter channel at https://gitter.im/fossasia/meilix

Actual Behaviour Changing Travis API request to point to your own fork of Meilix requires a change in the USER variable in build.py.

Expected Behaviour Ability to trigger Travis on a forked meilix repository using environment variables/config file

Related code: https://github.com/fossasia/meilix-generator/blob/c7d481d362e524bf4bb675c5b7cdd8e0e31c7332/build.py#L7-L9

Would you like to work on the issue? Yes