Move nox -s lint to GitHub Actions

.github/workflows/ci.yml

@@ -7,6 +7,21 @@ defaults:
     shell: bash
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v1
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v1
+        with:
+          python-version: 3.8
+      - name: Install dependencies
+        run: python3.8 -m pip install nox
+      - name: Lint the code
+        run: nox -s lint
+
   package:
     runs-on: ubuntu-latest
 

.travis.yml

@@ -33,8 +33,6 @@ jobs:
     - python: nightly
   include:
     # Lint & documentation.
-    - python: 3.8
-      env: NOX_SESSION=lint
     - python: 3.8
       env: NOX_SESSION=docs