openstack: Pin novaclient and keystoneclient package versions
openstack: Pin novaclient and keystoneclient package versions

meteorfox/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,AdamIsrael/PerfKitBenchmarker,meteorfox/PerfKitBenchmarker,AdamIsrael/PerfKitBenchmarker