Report code coverage (via Code Climate) in CI

[markets]

Closes #281
Closes #476
Closes #483

ℹ️ Docs: https://docs.codeclimate.com/docs/travis-ci-test-coverage#section-travis-ci-single-test-suite-non-parallel-builds

Pending:

• Add ENV var CC_TEST_REPORTER_ID
• Add coverage report badge in README

[enricostano]

@sseerrggii @enricostano @sauloperez guys could you please give me access to Code Climate account or send me this var and the badge code?

Sadly I don't know which account has been used to set this up. It's something from 6 years ago... @sseerrggii knows maybe?

If we don't know... maybe we can create a new account for Coopdevs and point to the new one.
I'm not even sure what do we use Codeclimate for a part from the badge, cannot find any integration settings related to it in GitHub.

EDIT: For performance, APM, etc we use Skylight, @sauloperez do you know if they also have something for coverage automation?

[markets]

maybe we can create a new account for Coopdevs and point to the new one

👍 Code Climate is very useful for code quality and coverage reports and free for open source! We can eventually integrate it with GH pull requests. Seems Skylight does not provide those kind of features: https://www.skylight.io/features

[markets]

@sseerrggii could you please open a new account in Code Climate? Then, I'll need access to this new account or I'll need someone to send me those couple of "codes"

[markets]

@enricostano @sauloperez ready

Thank you a lot @sseerrggii for providing me all the stuff! 👇

[enricostano]

😱

[enricostano]

@markets do you mind resolving the conflicts in this PR? Thanks!!! ❤️

[markets]

@enricostano done!

[enricostano]

@markets broken specs 😅 😬

[markets]

@enricostano rebased again, now are passing, but anyway that previous broken build isn't related to this branch (I'm only tweaking the .travis.yml here), seems an intermittent failure IMHO

[sauloperez]

I want those diff and total coverage reports in OFN 😱 ❤️