Release process

To create a new release of GPy, you must be a maintainer of the repository.

The steps required to release are:

1. Update the semantic versioning in GPy/__version__.py
2. Tag the devel branch using git tag v1.2.3 && git push --tags
3. Open a PR from devel to deploy on the commit you tagged in (2)
4. Once at least one other maintainer has agreed that it's ready, merge the PR into deploy

Upon merging the PR in step (4) above, the deploy section in .travis.yml will be executed to push the package built in CI to PyPi.