more fixes for pkg_resources shenanigans

Bug: 957577
Change-Id: I2f56e7a6bb72068438b09bc15169d6a04aec06ee
tests: fix Requires for slapadd

Change-Id: Ib82d31b73e0afab1bb69f6fa82a7355556d4d895
Merge changes Ib82d31b7,I2f56e7a6 into develop

* changes:
  tests: fix Requires for slapadd
  more fixes for pkg_resources shenanigans