Change SystemCollection from list to dict

- Change systems_list to systems_dict["<index>"] .
  The systems_dict will contain system objects, <index> is
  the redfish <index> as reported inside url.

redfish/main.py

@@ -247,8 +247,6 @@ class RedfishConnection(object):
                                                  self.connection_parameters
                                                  )
 
-        #for system in self.Systems.systems_list:
-            #config.logger.debug(system.data.links.ManagedBy)
 #         self.Chassis
 
 #         self.EventService

redfish/types.py

@@ -428,11 +428,12 @@ class SystemsCollection(BaseCollection):
     '''Class to manage redfish SystemsCollection data.'''
     def __init__(self, url, connection_parameters):
         super(SystemsCollection, self).__init__(url, connection_parameters)
-
-        self.systems_list = []
-
+       
+        self.systems_dict = {}
+        
         for link in self.links:
-            self.systems_list.append(Systems(link, connection_parameters))
+            index = re.search(r'Systems/(\w+)', link)
+            self.systems_dict[index.group(1)] = Systems(link, connection_parameters)
 
 
 class Bios(Base):