Add specs and code for editing projects.

Refactor out the form partial. Fixes #20.
Merge branch 'chapter-6' of github.com:codefellows/portfolio into chapter-6
Adding specs and code for User support.
Quick fix to test travis notifications
test github email hook with change to readme
merging in br branch
removing save_and_open_page
We can protect the blog from unauthenticated users
  with new helper method to sign in a user
  because devise helpers are not designed to work in capybara
	modified:   app/views/shared/_nav.html.erb
	modified:   test/features/posts/creating_a_post_test.rb
	modified:   test/features/posts/deleting_a_post_test.rb
	modified:   test/features/posts/editing_a_post_test.rb
	modified:   test/test_helper.rb