added instructions to install gym from paulhendricks/gym-R repository
added instructions to install gym from paulhendricks/gym-R repository

Lucsanszky/gym-http-api,Lucsanszky/gym-http-api,Lucsanszky/gym-http-api,Lucsanszky/gym-http-api,Lucsanszky/gym-http-api,Lucsanszky/gym-http-api,Lucsanszky/gym-http-api,Lucsanszky/gym-http-api,Lucsanszky/gym-http-api