GitHub actions (#369)

* Add initial workflow file

* Fix typo and remove .travis.yml

* Clean up

Author: Jskobos

.github/workflows/test.yaml

@@ -0,0 +1,30 @@
+name: Python package
+
+on: [pull_request]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.7.x'
+        architecture: 'x64'
+    - name: Cache pip
+      uses: actions/cache@v2
+      with:
+        path: ~/.cache/pip
+        # Look to see if there is a cache hit for the corresponding requirements file
+        key: ${{ runner.os }}-pip-${{ hashFiles('./ci/requirements.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
+          ${{ runner.os }}-
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install openapi3
+    - name: openapi linter
+      run: |
+        python -m openapi3 openapi.yaml