add github actions

.github/workflows/rust.yml

@@ -0,0 +1,18 @@
+name: Rust workflows
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: install rust nightly
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: nightly
+
+    - name: build project
+      run: cargo +nightly build --release