[BuildStream] Please try tox ! [Was: Update CI and testing process]

[Tristan Van Berkom <tristan vanberkom codethink co uk>]

Hi all,

We are now using tox (https://tox.readthedocs.org/) for running tests !

Please try running the tests on your own workstations using tox, and
let us know of any changes; if anything unexpectedly fails, or if what
used to fail on your workstation now passes.

On Sat, 2018-12-29 at 18:09 +0000, Chandan Singh wrote:
[...]
> To get there, I have created MR !1027 [1]. It is marked as WIP,  but
> it should be ready for review. The reason it is in WIP state is
> because before landing this, I would like to land the corresponding
> changes in the buildtream-docker-images [2] repo first. Once that
> happens, the testsuite images will no longer provide pure-Python
> runtime dependencies of BuildStream, but rather provide the non-Python
> build dependencies of our Python dependencies. Both MRs are in a
> merge-able state but I wanted to check with the community before
> making this change.

And it's landed !

Thanks Chandan for getting the tests to work with tox :)

It is my hope that with this branch, we can close:

   https://gitlab.com/BuildStream/buildstream/issues/570

The instructions for running tests and building docs have been updated 
to reflect the new usage of the tox frontend by default:

   https://docs.buildstream.build/CONTRIBUTING.html#testing

And the gitlab CI has been updated to build the docs and run tests
through tox.

Cheers,
    -Tristan