Add github actions.

Author: jdm

.github/workflows/rust.yml

@@ -0,0 +1,66 @@
+name: Rust
+
+on: 
+  push:
+    branches-ignore: "master"
+  pull_request:
+
+env:
+  SHELL: /bin/bash
+
+jobs:
+  fmt:
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: dtolnay/rust-toolchain@stable
+    - name: fmt check
+      run: cargo fmt --all -- --check
+  linux:
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: dtolnay/rust-toolchain@stable
+    - name: build
+      run: |
+        cd webxr
+        cargo build --features=glwindow,headless,googlevr
+        cargo build --features=ipc,glwindow,headless,googlevr
+        cargo build --features=glwindow,headless,profile
+        rustup target add arm-linux-androideabi
+        cargo build --target arm-linux-androideabi --features=ipc,googlevr
+  mac:
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: dtolnay/rust-toolchain@stable
+    - name: build
+      run: |
+        cd webxr
+        cargo build --features=glwindow,headless,googlevr
+        cargo build --features=ipc,glwindow,headless,googlevr
+        cargo build --features=glwindow,headless,profile
+  win:
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: dtolnay/rust-toolchain@stable
+    - name: build
+      run: |
+        cd webxr
+        cargo build --features=glwindow,headless,googlevr
+        cargo build --features=ipc,glwindow,headless,googlevr
+        cargo build --features=glwindow,headless,profile
+        rustup target add aarch64-pc-windows-msvc
+        cargo build --target=aarch64-pc-windows-msvc --features ipc,openxr-api
+  build_result:
+    name: homu build finished
+    runs-on: ubuntu-latest
+    needs: ["mac", "linux", "win", "fmt"]
+    steps:
+      - name: Mark the job as successful
+        run: exit 0
+        if: success()
+      - name: Mark the job as unsuccessful
+        run: exit 1
+        if: "!success()"