Add excel exporter in lib and change comments array to hash
removed unused view
Merge branch 'master' into feat/export_members_to_excel

Conflicts:
	app/controllers/admin/export_excel_controller.rb
	app/views/admin/export_excel/export.html.erb
export excel controller refactoring
Merge pull request #86 from DonutWorks/feat/export_members_to_excel

Feat/export members to excel  #81