Build examples and games on Travis CI

They were disabled because they failed to build,
but this patch set fixes the build on Linux and macOS.

This doesn't apply to the AppVeyor build on Windows yet;
it currently fails at linking with OpenAL.

games/wave_collector/wave_collector.c

@@ -63,7 +63,7 @@ static void UpdateDrawFrame(void);          // Update and Draw one frame
 #if defined(PLATFORM_ANDROID)
 void android_main(struct android_app *app) 
 #else
-int main(void)
+int main(int argc, char *argv[])
 #endif
 {
 	// Initialization
@@ -315,4 +315,4 @@ static void UpdateDrawFrame(void)
     
     EndDrawing();
     //----------------------------------------------------------------------------------
-}
+}