Start Date not working with --devs

[unixb0y]

Hello, another issue:
This command works as expected:

./hercules.darwin_amd64 --burndown --burndown-people repo-cache | labours -m ownership --start-date 13.11.2019

while in this case, the graph shows info from the start of the project and completely ignores the --start-date:

./hercules.darwin_amd64 --devs repo-cache | labours -m devs --start-date 13.11.2019

[vmarkovtsev]

Yes, --start-date is not implemented in the Python code for -m devs. Feel free to PR the fix everybody who sees this!