Add another shared object factory method flavor.

Code/Testing/RKTestFactory.h

@@ -144,6 +144,7 @@ extern NSString * const RKTestFactoryDefaultNamesManagedObjectStore;
  @return The shared object instance for the factory registered with the given name.
  */
 + (id)sharedObjectFromFactory:(NSString *)factoryName;
++ (id)sharedObjectFromFactory:(NSString *)factoryName properties:(NSDictionary *)properties;
 
 /**
  Inserts a new managed object for the `NSEntityDescription` with the given name into the specified  managed object context and sets properties on the instance from the given dictionary. A permanent managed object ID is obtained for the object so that it can be referenced across threads without any further work.

Code/Testing/RKTestFactory.m

@@ -94,12 +94,18 @@
 }
 
 - (id)sharedObjectFromFactory:(NSString *)factoryName
+{
+    return [self sharedObjectFromFactory:factoryName properties:nil];
+}
+
+- (id)sharedObjectFromFactory:(NSString *)factoryName properties:(NSDictionary *)properties
 {
     id sharedObject = [self.sharedObjectsByFactoryName objectForKey:factoryName];
     if (! sharedObject) {
         sharedObject = [self objectFromFactory:factoryName properties:nil];
         [self.sharedObjectsByFactoryName setObject:sharedObject forKey:factoryName];
     }
+    [sharedObject setValuesForKeysWithDictionary:properties];
     return sharedObject;
 }
 
@@ -171,6 +177,11 @@
     return [[RKTestFactory sharedFactory] sharedObjectFromFactory:factoryName];
 }
 
++ (id)sharedObjectFromFactory:(NSString *)factoryName properties:(NSDictionary *)properties
+{
+    return [[RKTestFactory sharedFactory] sharedObjectFromFactory:factoryName properties:properties];
+}
+
 + (id)insertManagedObjectForEntityForName:(NSString *)entityName
                    inManagedObjectContext:(NSManagedObjectContext *)managedObjectContext
                            withProperties:(NSDictionary *)properties