remove DOCKER HOST from Gitlab CI

.gitlab-ci.yml

@@ -11,8 +11,6 @@ services:
 
 variables:
   POSTGRES_DB: postgres
-  DOCKER_HOST: tcp://localhost:2375/
-  DOCKER_API_VERSION: "1.39"
 
 # This folder is cached between builds
 # http://docs.gitlab.com/ce/ci/yaml/README.html#cache
@@ -54,7 +52,7 @@ test-backend:
     - cd backend
     - pipenv install --dev --system --deploy
     - flake8 --max-line-length 120
-    - until pg_isready -h ${DATABASE_HOST}; do echo waiting; sleep 2; done;
+    - until pg_isready; do echo waiting; sleep 2; done;
     - pytest --cov .
 
 deploy-dev: