Merge pull request #311 from styled-components/gh-actions

switch to github actions

.github/workflows/test.yml

@@ -0,0 +1,26 @@
+name: CI
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node: ["10", "12", "14"]
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/cache@v2
+        with:
+          path: "**/node_modules"
+          key: ${{ runner.os }}-modules-${{ hashFiles('**/yarn.lock') }}
+
+      - name: Install modules
+        run: yarn
+
+      - name: Setup node
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node }}
+
+      - name: Run tests
+        run: yarn test