This commit removes the command to install PHPUnit on every Travis build job. I'm doing this because I don't see a reason for WooCommerce to re-install PHPUnit since it is already installed by default on every build job. Travis automatically handles installing the right PHPUnit version for each PHP version that we use.
This change should save around 10 seconds from each build job (https://travis-ci.org/woocommerce/woocommerce/jobs/306623161#L515).
PR #17680 added a new PHP 7.1 Travis build job to generate code coverage report. PHPCS was configured to run on all PHP 7.1 build jobs. So this means that after #17680 was merged, Travis started running PHPCS twice.
This commit fixes this issue by setting a new environment variable called `$RUN_PHPCS` and using this variable, instead of the PHP version, to decide when to run PHPCS.
Travis build is taking about 40 minutes to complete, and that is mostly because of the generation of the code coverage report.
To address that, this commit changes Travis configuration to run the command to generate code coverage report on a separate non-blocking Travis job. This way once the jobs that run the tests finishes, Travisi will mark the build as successful and will keep running code coverage on a separate job.
This commit removes Xdebug from PHP runtime on all build jobs except PHP 7.1 to speed up Travis builds. Xdebug is needed in the PHP 7.1 build job because this job is used to generate code coverage.
Claudio Sanches
Rodrigo Primo
Mike Jolley
Jon Surrell
Claudio Sanches
Shiva Poudel
Ramon van Belzen
Max Rice