Proton support (#64)

Enable proton for heroic games

src/uplay/platform.rs

@@ -42,6 +42,16 @@ impl Platform<Game, Box<dyn Error>> for Uplay {
     fn create_symlinks(&self) -> bool {
         false
     }
+
+    fn needs_proton(&self, _input: &Game) -> bool {
+        #[cfg(target_os = "windows")]
+        return false;
+        #[cfg(target_family = "unix")]
+        {
+            //TODO update this when uplay gets proton support on linux
+            return true;
+        }
+    }
 }
 
 #[cfg(target_os = "windows")]