According to stubs from mypy 0.4.7 onwards, `requests.get` takes
a parameter `params` of type `Dict[AnyStr, AnyStr]` where `AnyStr`
can be either bytes or text. Actually, requests can accept values
of other types in dicts too but it casts them to a string type.
So to avoid type checking error messages, change `True` to `'True'`.