Added functionality for deleting uploaded files.  

Make delete request to ..../applications/upload
URL Params:
	Long applicationId : The Id of the application to which the file is
attached
	String fileName : the name of the file including the type extension
	
Returns 200 if successfull or error code/message if failed.
Merge branch 'master' of https://github.com/DataAnalyticsinStudentHands/TerryApplication.git