Revert "Rename requirements_notes.md to requirements.md"

This reverts commit 661bcb3b9d40934b4dc5f8b38e886c57143268dc.
Renamed DataSet to Dataset
Renamed DataSet to Dataset
Merge pull request #31 from bennovack/master

Renamed DataSet to Dataset
Fixed terrible build-breaking typo
Merge branch 'master' of https://github.com/PhillyHealthDataRepo/philly-open-health
Merge branch 'master' into torresga-new_auth

Conflicts:
	app/controllers/data_sets_controller.rb
	db/schema.rb