CI upgrade

[kidunot89]

Your checklist for this pull request

Thanks for sending a pull request! Please make sure you click the link above to view the contribution guidelines, then fill out the blanks below.

🚨Please review the guidelines for contributing to this repository.

• Make sure you are making a pull request against the develop branch (left side). Also you should start your branch off our develop.
• Make sure you are requesting to pull request from a topic/feature/bugfix branch (right side). Don't pull request from your master!

What does this implement/fix? Explain your changes.

• Modifies .travis.yml to run tests using docker tests environment instead of locally.
• Docker-compose configuration for quickly setting up a test environment.
  • Run docker-compose up --scale testing=0 --scale testing_db=0 to get a local WP app running with all the necessary dependencies to use WooGraphQL installed and activated. By default the docker container is parked at http://localhost:8001
  • Run docker-compose run -e SUITE=suite_name testing --rm testing --scale app=0. To run a test suite inside a docker container. You get codecoverage or debug/verbose output by setting the a COVERAGE or DEBUG environment variables on the testing container like the SUITE environment variable in the example above.
  • The docker-compose.yml initial setting rely on the values in env.dist and codeception.dist.yml. So altering them is not recommend unless you wish to change the behavior of the docker-compose.yml.

Does this close any currently open issues?

…

Any relevant logs, error output, GraphiQL screenshots, etc?

(If it’s long, please paste to https://ghostbin.com/ and insert the link here.)

Any other comments?

…

Where has this been tested?

Operating System: Ubuntu 18.04

WordPress Version: 5.2