Requirments outdated

[Chwiggy]

Trying to add transit service analyst to your project has grown hard based on outdated requirements definitions.

From gtfs_service.py:

from numpy import NaN

Numpy beyond version 2.0.0 renamed NaN to nan, but with a requirements.txt with numpy>=1.16.1 versions beyond 2.0.0 satisfy the stated requirements.

[stefancoe]

@Chwiggy Sorry for the delay. I will try to patch this up this weekend.

[stefancoe]

@Chwiggy I have updated requirements.txt. I am going to update the code to be compatible with more recent versions of numpy and pandera and will issue a new release soon, but this will require new minimum versions for both of these packages.