Order the excel responses in the order of their `updated_at` fields.
Show the number of answers for a question along with the reports.
set response to incomplete if it's not valid for ResponseController#update action
Added a private method to destory response
Updated Rails to 3.2.12
Fixed the failing build by adding a presisted check to destory_response method
Duplicated surveys shouldn't be public if the orignal survey was public
Added a method to unpublish users
Added mobile_id column for responses.

Conflicts:
	db/schema.rb
Require the response to not exist before creating. Find response by mobile_id.
Added unpublish method to publication controller
Added unpublish page for a survey
Don't make a query to fetch each answer of a response separately. Fetch them all at once.

Conflicts:

	app/views/responses/index.xlsx.axlsx
Eager loading choices along with answers while downloading excel.

Conflicts:

	app/views/responses/index.xlsx.axlsx
Eager load options along with choices while downloading excel foe a survey.

Conflicts:

	app/views/responses/index.xlsx.axlsx
Check for an existing answer before create using mobile_id only if mobile_id is passed with the params in API::ResponsesController
Added config to run unicorn on heroku (survey-web-develop)
Added destroy action to publication controller
Fixed minor issues with the unpublish flow