Add BitBucket Config

[ataylorme]

bitbucket-pipelines.yml implements:

• static tests
• PHP build
• deploy to Pantheon
• visual regression tests
• Behat tests
• Composer Lock Updater

[ataylorme]

I've tested on master but still need to make a PR

[aaronbauman]

Looks like installing a different version of build tools via BUILD_TOOLS_VERSION doesn't work.

Whatever happens during Configure Environment Variables step is ignored by subsequent steps.

Maybe can create a cache for ~/.terminus/plugins ?

[ataylorme]

@aaronbauman I created a bleeding-build-tools tag of the quay.io/pantheon-public/build-tools-ci image that has Build Tools on dev-master. I am testing on that and, once testing is done, will tag a new beta and update 6.x.

However, BUILD_TOOLS_VERSION not working isn't good

[ataylorme]

I have a passing build looking the way I want, minus Composer Lock Updater, with Build Tools beta 16 and the 6.x Dockerfile: https://bitbucket.org/ataylorme/example-wp-composer-pipelines-test-2019-09-10/addon/pipelines/home#!/results/18

I think this is good to go!

[aaronbauman]

LGTM

I've filed a separate issue pantheon-systems/example-drops-8-composer#279 that's preventing viz-reg tests from running.