Log Message:
py-isc_dhcp_leases: update to 0.10.0

No change log published, but changes are:

Fix timezone awareness for Python 2.7.x
Support working with historical dhcpd.leases files
Use timezone-aware datetime objects
Refactor keyword argument passing to BaseLease

All those changes were previously included in pkgsrc patches, so there
is no new functionality, this is simply aligning with the new upstream
release state.