Merge pull request #29 from tetianahogg/dev

Task 2. Sign in/up views and logic.
Merge pull request #42 from tetianahogg/dev

Controllers, views..
Merge pull request #58 from tetianahogg/dev

Search, validates, share survey, add questions
Merge pull request #64 from tetianahogg/dev

changes
Merge pull request #68 from tetianahogg/dev

Last changes.
Fixed
Fixed layout ISS71
Added Copy link button on sharing page
Fixed issue when you create survey without questions
Added 'Back' button
Fixed bugs with factories