Fixed serializer types

app/serializers/api/v1/connection_serializer.rb

@@ -3,7 +3,7 @@
 module Api
   module V1
     class ConnectionSerializer < ActiveModel::Serializer
-      type :connection
+      type :connections
       attributes :id, :input_id, :output_id
     end
   end

app/serializers/api/v1/experiment_serializer.rb

@@ -3,7 +3,7 @@
 module Api
   module V1
     class ExperimentSerializer < ActiveModel::Serializer
-      type :experiment
+      type :experiments
       attributes :id, :name, :description, :project_id, :created_by_id,
                  :archived, :created_at, :updated_at
     end

app/serializers/api/v1/my_module_group_serializer.rb

@@ -3,7 +3,7 @@
 module Api
   module V1
     class MyModuleGroupSerializer < ActiveModel::Serializer
-      type :MyModuleGroup
+      type :task_groups
       attributes :id, :created_at, :updated_at, :created_by_id, :experiment_id
       belongs_to :experiment, serializer: ExperimentSerializer
     end