Update workflow actions to latest version(s)

.github/workflows/ci.yml

@@ -1,26 +1,32 @@
 name: ci
 
-on: [push]
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+  workflow_dispatch:
 
 jobs:
-  build:
+  ci:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - name: Checkout Git repository
+        uses: actions/checkout@v3
 
-      - name: Setup Python 3.6
-        uses: actions/setup-python@v1
+      - name: Setup Python
+        uses: actions/setup-python@v4
         with:
-          python-version: 3.6
+          python-version: 3.8
 
-      - name: Install dependencies
+      - name: Install Python dependencies
         run: |
           python -m pip install --upgrade pip
           pip install flake8
           pip install pydocstyle
 
-      - name: Lint with flake8
+      - name: Lint with flake8 and pydocstyle
         run: |
           flake8 . --max-line-length=120 --show-source --statistics
           pydocstyle . --add-ignore=D202