Merge pull request #21 from santisamra/master

User-Project association backend
issue #10, backend
Merge pull request #22 from ConcoMB/issue-10

issue #10, backend
Finished milestones in projects #6
agrupamiento basico  #13
Upgrade ruby version
Fix bug that occur when there was no active milestone
Fix bug when retrieving project milestone
ix project milestone layout
Fix accordion
Merge pull request #24 from framundo/master

Milestones finished
Merge and add models and views for backbone

Conflicts:
	app/assets/javascripts/backbone/routers/project_router.js.coffee
	app/assets/stylesheets/projects.css.less
	app/controllers/projects_controller.rb
	app/views/projects/show.html.haml