The change implements LBaaS CLI commands.

Implements: blueprint lbaas-cli

New commands:
 * Vip: lb-vip-create, lb-vip-list, lb-vip-show, lb-vip-update,
   lb-vip-delete
 * Pool: lb-pool-create, lb-pool-list, lb-pool-show, lb-pool-update,
   lb-pool-delete, lb-pool-stats
 * Member: lb-member-create, lb-member-list, lb-member-show,
   lb-member-update, lb-member-delete
 * Health Monitor: lb-healthmonitor-create, lb-healthmonitor-list,
   lb-healthmonitor-show, lb-healthmonitor-update, lb-healthmonitor-delete,
   lb-healthmonitor-associate, lb-healthmonitor-disassociate

Change-Id: Idaa569024c24955886a836e3dfedd009fed87007