Build/Test Tools: Pass the TRAVIS_BRANCH and TRAVIS_PULL_REQUEST environment variables along to the Docker container.

This ensures that `WP_UnitTestCase::skipOnAutomatedBranches()` has access to these variables.

See #49050, #47767.

git-svn-id: https://develop.svn.wordpress.org/trunk@46999 602fd350-edb4-49c9-b593-d223f7449a82

docker-compose.yml

@@ -105,6 +105,8 @@ services:
       WP_MULTISITE: ${WP_MULTISITE-false}
       PHP_FPM_UID: ${PHP_FPM_UID-1000}
       PHP_FPM_GID: ${PHP_FPM_GID-1000}
+      TRAVIS_BRANCH: ${TRAVIS_BRANCH-false}
+      TRAVIS_PULL_REQUEST: ${TRAVIS_PULL_REQUEST-false}
 
     volumes:
       - ./tools/local-env/phpunit-config.ini:/usr/local/etc/php/conf.d/phpunit-config.ini