Move linter to separate step (#608)

Author: Dreamsorcerer

.github/workflows/ci.yaml

@@ -21,10 +21,12 @@ jobs:
       run: |
         pip install --upgrade pip
         pip install -r requirements-dev.txt
+    - name: Run linters
+      run: |
+        make mypy
     - name: Run tests
       run: |
         make cov
-        make mypy
         python setup.py check -rms
     - name: Upload coverage
       uses: codecov/codecov-action@v1