Feature/integration tests config

[vpodorozh]

Introducing integration tests configs:

• yml pipeline config
• phpunit template config

[DavidLambauer]

HI @vpodorozh,

thank you for the PR.

@mwr and I reviewed this PR, and we have the following change requests:

• Please remove magento2/integration-tests/phpunit-integration.xml.dist. This file should always be project specific
• The config.php is also always project-specific. Please use an env var with the path's default to the default config.php
• Please research if the services can be configured through an env var. The elasticsearch version, for example can change between multiple Magento Versions