Use environment markers for Python 2 dependency pins (#3618)
Use environment markers for Python 2 dependency pins (#3618)

PyPI does not run setup.py separately for each Python version to
resolve requirements, so these conditional requirements need to be
properly specified in the metadata, not in code.

Signed-off-by: Anders Kaseorg <087231934ba8fcf78bc142ce37d193b895ac03c4@mit.edu>
william-richard/moto,william-richard/moto,william-richard/moto,william-richard/moto,spulec/moto,spulec/moto,spulec/moto,spulec/moto,spulec/moto,spulec/moto,william-richard/moto,william-richard/moto