Add crates.io GitHub action

.github/workflows/crates.yml

@@ -0,0 +1,22 @@
+name: Crates.io Release
+
+on:
+  push:
+    tags:
+      - v*
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Check style
+      run: cargo fmt -- --check
+    - name: Build
+      run: cargo build --verbose
+    - name: Run tests
+      run: cargo test --verbose
+    - name: Publish
+      run: cargo publish --token ${{ secrets.CRATES_IO_TOKEN }}