Switch to gitlab ci

.gitlab-ci.yml

+stages:
+  - test
+
+test:
+  image: python:3.7
+  stage: test
+  variables:
+    CONFIG_FILE: ${CI_PROJECT_DIR}/ci_config.yaml
+  before_script:
+    - pip install pipenv
+    - pip install flake8
+    - pipenv install --system --dev --ignore-pipfile
+    - pipenv run src/manage.py migrate
+  script:
+    - pipenv run src/manage.py test src/
+    - flake8

.travis.yml

-sudo: required
-dist: xenial
-language: python
-
-python:
-  - "3.6"
-
-services:
-  - postgresql
-
-env:
-  - CONFIG_FILE=${TRAVIS_BUILD_DIR}/travis_config.yaml
-
-before_install:
-  - sudo apt-get update
-  - sudo apt-get install -y graphviz-dev
-
-install:
-  - pip install pipenv
-  - pip install flake8
-  - pipenv lock
-  - pipenv install --system --dev
-
-before_script:
-  - pipenv run src/manage.py migrate
-
-script:
-  - pipenv run src/manage.py test src/
-  - flake8
\ No newline at end of file