Add Gameserver information

It is now possible to get game server information using the [GET] /v1/gameserver/{server_id} endpoint of CFTools Cloud. This endpoint/method does not require authentication.

Also changed:

• Made withCredentials and withServerApiId optional, as not all methods require these information anymore
• Provide a way to override the server api ID per request for methods/endpoints that require one

README fixes

v1.0.3

1.0.3

1.0.2

v1.0.2

1.0.2