Update GET /teams, GET teams/:team_id endpoints slightly

app/controllers/api/v1/teams_controller.rb

@@ -13,7 +13,9 @@ module Api
       end
 
       def show
-        render jsonapi: @team, serializer: TeamSerializer
+        render jsonapi: @team,
+               serializer: TeamSerializer,
+               include: :created_by
       end
 
       private

app/serializers/api/v1/team_serializer.rb

@@ -4,6 +4,7 @@ module Api
   module V1
     class TeamSerializer < ActiveModel::Serializer
       attributes :id, :name, :description, :space_taken
+      belongs_to :created_by, serializer: UserSerializer
     end
   end
 end