Added Jquery-masonry-gem for pins

	modified:   Gemfile
	modified:   Gemfile.lock
	modified:   app/assets/javascripts/application.js
	modified:   app/assets/javascripts/pins.js.coffee
	modified:   app/assets/stylesheets/application.css
	modified:   app/assets/stylesheets/pins.css.scss
	modified:   app/views/layouts/_navigation.html.erb
	modified:   app/views/pins/index.html.erb