add ability to change namespace from project edit page

app/models/ability.rb

@@ -7,6 +7,7 @@ class Ability
       when "Note" then note_abilities(object, subject)
       when "Snippet" then snippet_abilities(object, subject)
       when "MergeRequest" then merge_request_abilities(object, subject)
+      when "Group" then group_abilities(object, subject)
       else []
       end
     end
@@ -61,6 +62,16 @@ class Ability
       rules.flatten
     end
 
+    def group_abilities user, group
+      rules = []
+
+      rules << [
+        :manage_group
+      ] if group.owner == user
+
+      rules.flatten
+    end
+
     [:issue, :note, :snippet, :merge_request].each do |name|
       define_method "#{name}_abilities" do |user, subject|
         if subject.author == user