Implement CSV importer for agency data

Give admin ability to import a large number of agencies at a time, using spreadsheet that includes agency address, contacts, etc. along with what kinds of food they can accept. 
*accepted food types are in the form of 0's and 1's, per each food type id determined by Feeding America. 

just delete the `@agency_data = `. It looks weird but whatever. Then you can just do `Agency.create(collect_agency_data(row_data, food_type_ids)`. Maybe rename, and then I think you can work on getting rid of the arguments.