missing env var

Author: 3nids

.docker/docker-compose.travis.yml

@@ -17,3 +17,4 @@ services:
       - TRAVIS_PULL_REQUEST_BRANCH=${TRAVIS_PULL_REQUEST_BRANCH}
       - TRAVIS_COMMIT_RANGE=${TRAVIS_COMMIT_RANGE}
       - TRAVIS_OS_NAME=${TRAVIS_OS_NAME}
+      - TRAVIS_CONFIG=${TRAVIS_CONFIG}