add new continuous integration file

triple-dungeon/.github/workflows/ci.yml

@@ -0,0 +1,31 @@
+name: Continuous Integration (PEP8 Lint + pytest)
+
+on: push
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python 3.7
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.7
+    - name: Install pipenv & sync
+      run: |
+        cd triple-dungeon
+        python -m pip install --upgrade pip
+        pip install pipenv
+        pipenv lock
+        pipenv sync
+    - name: Linting
+      run: |
+        pip install pycodestyle
+        # PyCharm sets line length at 120 chars
+        pycodestyle . --count --statistics --max-line-length=120
+    - name: Test with pytest
+      run: |
+        pip install pytest
+        pytest tests.py