fix: rework black github action

Author: ziirish

.github/workflows/black.yml

@@ -0,0 +1,10 @@
+name: Lint
+
+on: [push, pull_request]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: psf/black@stable

.github/workflows/test.yml

@@ -10,31 +10,7 @@ on:
     - cron: "0 1 * * *"
   workflow_dispatch:
 jobs:
-  checks:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Set up Python 3.8
-        uses: actions/setup-python@v1
-        with:
-          python-version: 3.8
-      - name: Checkout code
-        uses: actions/checkout@v2
-      - name: Install dependencies
-        run: |
-          python -m pip install --upgrade pip
-          pip install ".[dev]"
-      - name: Format with black
-        run: |
-          if ! RES=$(black --check $(git diff --name-only --diff-filter=AM master -- "*.py") 2>&1); then
-            RES="${RES//'%'/'%25'}"
-            RES="${RES//$'\n'/'%0A'}"
-            RES="${RES//$'\r'/'%0D'}"
-            echo "::error ::${RES}"
-            exit 1
-          fi
-          echo ${RES}
   unit-tests:
-    needs: checks
     runs-on: ubuntu-latest
     strategy:
       matrix: