added instrument field.
added ability to show all registered users.
added menu items and links.
Merge pull request #26 from sunny-mittal/gabe

Gabe
Merge branch 'nManos'
Merge branch 'master' of https://github.com/sunny-mittal/class-project

Conflicts:
	app/assets/stylesheets/application.css
	app/models/user.rb
db and popup fix
Rubocop errors fix