Replace travis-ci with github actions for CI.

.github/workflows/tests.yaml

@@ -0,0 +1,23 @@
+name: Tests
+on: [push]
+jobs:
+  tests:
+    name: ${{ matrix.python-version }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: [3.6, 3.7, 3.8]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: package deps
+        run: |
+          sudo apt-get install libsqlcipher-dev
+          python setup.py build_ext -i
+      - name: runtests
+        env:
+          PYTHONPATH: '.:$PYTHONPATH'
+        run: python test/