Merge install, lint and test steps

Probably necessary because of the virtualenv

.drone.yml

@@ -14,18 +14,12 @@ trigger:
     - main
 
 steps:
-  - name: install
+  - name: install-lint-test
     image: registry.wtf-eg.net/ki-backend-builder:1.0.0
     commands:
       - pipenv install --dev
-  - name: lint
-    image: registry.wtf-eg.net/ki-backend-builder:1.0.0
-    commands:
       - pipenv run flake8
       - pipenv run reuse lint
-  - name: test
-    image: registry.wtf-eg.net/ki-backend-builder:1.0.0
-    commands:
       - pipenv run python -m unittest discover ki
 
 image_pull_secrets: