ci: remove Commitlint workflow (replaced by semantic-pull-request) (#25)

* ci: remove Commitlint workflow (replaced by semantic-pull-request)

* ci: fix doctests not running correctly on some OS and Python versions

.github/workflows/commitlint.yml

@@ -1,21 +0,0 @@
-name: Commit
-
-on:
-  push:
-    branches: [main, features]
-  pull_request:
-    branches: [main, features]
-
-jobs:
-  commitlint:
-    name: Message validation
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v2
-      with:
-        fetch-depth: 0
-    - uses: wagoid/commitlint-github-action@v2
-      with:
-        helpURL: 'https://github.com/Kosmorro/kosmorro/blob/master/CONTRIBUTING.md#commiting'
-

.github/workflows/tests.yml

@@ -108,8 +108,8 @@ jobs:
       run: |
         make coverage-doctests
 
-    - name: Run doc tests
-      if: ${{ matrix.os != 'ubuntu-20.04' && matrix.python_version != '3.9' }}
+    - name: Run doc tests (without coverage)
+      if: ${{ matrix.os != 'ubuntu-20.04' || matrix.python_version != '3.9' }}
       run: |
         make doctests