This migrates the above files from tempest. This includes tempest commits:
* keypairs_client.py : I5bbc2c15155e6a25da7c44d00d5ac1214c0462bf
* keypairs.py : Ica929c402a3d042ae751302384e68853eb28b405
* test_keypairs_client.py: I3ad6761651cec5e66012d08e6b63322f53286a5c
to see the commit history for these files refer to the above Change-Ids in
the tempest repository.
Partially implements blueprint migrate-service-clients-to-tempest-lib
Change-Id: I825e54c23be673725afc6d89104ff12c2363890f