Add gtk to github action build

Author: PolyMeilex

.github/workflows/rust.yml

@@ -8,7 +8,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Install alsa
-        run: sudo apt-get install libasound2-dev
+        run: sudo apt-get install libasound2-dev libgtk-3-dev
       - name: Build
         run: cargo build --release --verbose
       - name: Run tests