Move to pygit2 v0.21
Update to pygit2 0.21.1
Revert "Move to pygit2 v0.21"

This reverts commit f8f9e452f2eb516d0e05ef689136607f3d1595dd.
Support pygit2 since 0.19
Trying to get "pip install itools" to work
Get ready to releas 0.75.2