Switch to GitHub Actions CI. (#220)

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.github/workflows/test.yml

@@ -0,0 +1,34 @@
+name: Tests
+on: [push, pull_request]
+env:
+  CI: true
+
+jobs:
+  run:
+    name: Node ${{ matrix.node }} on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        # switch to `8` when https://github.com/actions/setup-node/issues/27 is fixed
+        node: [8.16.1, 10, 12]
+        os: [ubuntu-latest, windows-latest]
+
+    steps:
+      - name: Clone repository
+        uses: actions/checkout@v1
+
+      - name: Set Node.js version
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node }}
+
+      - run: node --version
+      - run: npm --version
+
+      - name: Install npm dependencies
+        run: npm ci
+
+      - name: Run tests
+        run: npm test

README.md

@@ -1,12 +1,10 @@
-# PostCSS Image Inliner [![Build Status][ci-img]][ci] [![Windows Build Status][winci-img]][winci]
+# PostCSS Image Inliner [![Build Status][ci-img]][ci]
 
 [PostCSS] plugin to inline local/remote images.
 
 [PostCSS]: https://github.com/postcss/postcss
-[ci-img]: https://travis-ci.org/bezoerb/postcss-image-inliner.svg
-[ci]: https://travis-ci.org/bezoerb/postcss-image-inliner
-[winci-img]: https://ci.appveyor.com/api/projects/status/5xaq0ord84y5ho0c?svg=true
-[winci]: https://ci.appveyor.com/project/bezoerb/postcss-image-inliner
+[ci-img]: https://github.com/bezoerb/inline-critical/workflows/Tests/badge.svg
+[ci]: https://github.com/bezoerb/inline-critical/actions?workflow=Tests
 
 ```css
 .foo {