Bump setup-miniconda from v1 to v2 and remove Travis CI

[weiji14]

Fixes Github Actions CI error:

Error: Unable to process command '::add-path::/usr/share/miniconda/condabin' successfully.
Error: The `add-path` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/

[martindurant]

Should we disable travisCI now?

[weiji14]

Sure, keep things simple. Do it in this PR or another one?

[martindurant]

Would b happy to see it done here. I actually don't know how! I turned off builds in the travis UI (well, the one on .com, where this repo shows up, but not apparently where the build happens...)

[weiji14]

Would b happy to see it done here. I actually don't know how! I turned off builds in the travis UI (well, the one on .com, where this repo shows up, but not apparently where the build happens...)

I've deleted the .travis.yml file which should do the trick 😆

[martindurant]

Great