Split CI pipeline into 2 stages, added mypy check.

.gitlab-ci.yml

@@ -1,18 +1,26 @@
 ---
 image: debian:buster
 
+stages:
+- test
+- codestyle
+
 test:
+  stage: test
   script:
   - apt-get update -qy
   - apt-get install -y --no-install-recommends python3-dev python3-pip python3-coverage python3-setuptools build-essential
+  - pip3 install wheel
   - pip3 install -r requirements.txt
   - python3-coverage run --branch -m unittest discover matemat
   - python3-coverage report -m --include 'matemat/*' --omit '*/test_*.py'
 
 codestyle:
+  stage: codestyle
   script:
   - apt-get update -qy
   - apt-get install -y --no-install-recommends python3-dev python3-pip python3-coverage python3-setuptools build-essential
+  - pip3 install wheel pycodestyle mypy
   - pip3 install -r requirements.txt
-  - pip3 install pycodestyle
   - pycodestyle matemat
+  - mypy matemat

requirements.txt

@@ -1,3 +1,2 @@
-wheel
 bcrypt
 apsw