Add actions workflow to publish crate

Author: zakcutner

.github/workflows/publish.yml

@@ -0,0 +1,14 @@
+name: Publish
+on: release
+jobs:
+  cargo:
+    name: Cargo
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          default: true
+      - env: CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
+        run: cargo login "$CARGO_REGISTRY_TOKEN"
+      - run: cargo publish