Add GitHub action for running cargo publish

.github/workflows/publish.yml

@@ -0,0 +1,19 @@
+on:
+  push:
+    branches:
+      - master
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Checkout submodules
+        shell: bash
+        run: |
+          auth_header="$(git config --local --get http.https://github.com/.extraheader)"
+          git submodule sync --recursive
+          git -c "http.extraheader=$auth_header" -c protocol.version=2 submodule update --init --force --recursive --depth=1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+      - run: cargo publish