Adds selected memoization

Page load times in tuskar-ui are too slow.  This patch adds some
caching to the tuskarclient and its list function to reduce page
load time.  Tests locally showed these changes decreased page load
time by half in a virt environment.

Change-Id: Ib5d67dc2c1a58011739b81156fa50f5cccb223d4

tuskar_ui/api/tuskar.py

@@ -39,6 +39,7 @@ KEYSTONE_CERTIFICATE_PARAMS = (
     'KeystoneSigningKey')
 
 
+@memoized.memoized
 def tuskarclient(request, password=None):
     api_version = "2"
     insecure = getattr(settings, 'OPENSTACK_SSL_NO_VERIFY', False)
@@ -152,6 +153,7 @@ class Plan(base.APIResourceWrapper):
         return cls(plan, request=request)
 
     @classmethod
+    @memoized.memoized
     def list(cls, request):
         """Return a list of Plans in Tuskar