Add push action - build.

.github/workflows/push-build.yml

@@ -0,0 +1,16 @@
+name: Rust
+
+on: push
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Build
+      run: cargo build --verbose --release
+    - name: Strip
+      run: strip target/release/tmux-helper
+