fix some errors with controllers/serializers

app/controllers/main_controller.rb

@@ -175,7 +175,7 @@ class MainController < ApplicationController
     end
 
     #limit to 5 results
-    @synapses = @synapses.slice(0,5)
+    @synapses = @synapses.to_a.slice(0,5)
 
     render json: autocomplete_synapse_array_json(@synapses)
   end 

app/serializers/event_serializer.rb

@@ -1,5 +1,4 @@
 class EventSerializer < ActiveModel::Serializer
-  embed :ids, include: true
   attributes :id, :sequence_id, :kind, :map_id, :created_at
 
   has_one :actor, serializer: NewUserSerializer, root: 'users'

app/serializers/new_map_serializer.rb

@@ -1,5 +1,4 @@
 class NewMapSerializer < ActiveModel::Serializer
-  embed :ids, include: true
   attributes :id,
              :name,
              :desc,

app/serializers/new_mapping_serializer.rb

@@ -1,5 +1,4 @@
 class NewMappingSerializer < ActiveModel::Serializer
-  embed :ids, include: true
   attributes :id,
              :xloc,
              :yloc,

app/serializers/new_synapse_serializer.rb

@@ -1,5 +1,4 @@
 class NewSynapseSerializer < ActiveModel::Serializer
-  embed :ids, include: true
   attributes :id,
              :desc,
              :category,

app/serializers/new_topic_serializer.rb

@@ -1,5 +1,4 @@
 class NewTopicSerializer < ActiveModel::Serializer
-  embed :ids, include: true
   attributes :id,
              :name,
              :desc,