Pin mock for testing on python2
This PR pins mock
to <4.0.0a0
on python 2, since 4.0.0 is python3-only, but pip
has no idea how to respect that. This should fix the build failures seen in #1209, etc.
This PR pins mock
to <4.0.0a0
on python 2, since 4.0.0 is python3-only, but pip
has no idea how to respect that. This should fix the build failures seen in #1209, etc.