Requirements and update to cocoeval.py

[wmcnally]

Thank you for this great repo! The requirements should be updated. I had to try several different package versions to get this running. Below is the environment I got it working with. Also, cocoeval.py should be updated with this fix.

Output of $ pip freeze:

certifi==2021.10.8
colour==0.1.5
cycler==0.11.0
Cython==0.29.27
fonttools==4.29.1
imageio==2.15.0
Jinja2==3.0.3
kiwisolver==1.3.2
MarkupSafe==2.0.1
matplotlib==3.5.1
networkx==2.6.3
numpy==1.21.5
packaging==21.3
Pillow==9.0.1
pycocotools==2.0.2
pyparsing==3.0.7
python-dateutil==2.8.2
PyWavelets==1.2.0
scikit-image==0.18.0
scipy==1.1.0
six==1.16.0
tifffile==2021.11.2