Update the requirement.txt for gym-minigrid

[pdx97]

The correct version of gym-minigrid which works is 1.1.0 when I was trying to run the visualize file for my trained model I was facing some env.render error in it said the following error
"result = env.render(*args, **kwargs)
TypeError: render() takes 1 positional argument but 2 were given "
so when I upgraded it to 1.1.0 then only it worked .

[lcswillems]

Fixed in last commit. It should now work with version 2.2 of Minigrid.