added authentication helper
user can sign out
created SalesReader and setup method to read file
SalesReader creates instances of Item, Sale, Company, and Customer. Models are not yet made
added test files for all models created by SalesReader
created customer model
added company model
created item model
created sale model
added model SalesSet
added factories for each model
cleaned up tests to use factories
only authenticated users can now upload a sales csv
added README and re ran rake db:create and migrate
added bad csv file
added unhappy path for uploading a csv
added content to README