This patch adds a Horizon plugin for Blazar. The following features are
currently supported:
* Show a list of leases
* Show details of a lease
* Update a lease
* Delete lease(s)
Change-Id: I24c14e697d4280fa29d84d11324fb881009f089b
Partially Implements: blueprint climate-dashboard
Co-Authored-By: Pablo Andres Fuente <pablo.a.fuente@intel.com>