Add github workflows for running tests on multiple python versions (#23)

.github/workflows/test.yml

@@ -0,0 +1,22 @@
+name: Test
+on: [push, pull_request]
+jobs:  
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: [3.7, 3.8, "3.10"]
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install Python ${{ matrix.python-version }} dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install .
+      - name: Run pytest
+        run: pytest