Create rust.yml (#3)

+ added a workflow file for CI

.github/workflows/rust.yml

@@ -0,0 +1,25 @@
+name: Rust
+
+on:
+  push:
+    branches: [ ref-method ]
+  pull_request:
+    branches: [ master ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: check
+      run: cargo check --verbose
+    - name: Build
+      run: cargo build --verbose
+