Install libsdl2

Author: jonathanpallant

.github/workflows/rust.yml

@@ -10,4 +10,7 @@ jobs:
     steps:
     - uses: actions/checkout@v1
     - name: Build
-      run: cargo build --verbose
+      run: |
+        sudo apt-get update -y
+        sudo apt-get install -y libsdl2-dev libsdl2-mixer-dev libsdl2-ttf-dev libsdl2-image-dev libsdl2-gfx-dev
+        cargo build --verbose