Add icons to tags

- add iconURL to tags model
- retrieve icon when loading tags tableView
Logs and formatting
Update gitignore
Update tags tableview
Button with voxe logo
Update rakefile & TestFlight config (without tokens)
Choose election
Simplify election selection
Only display back button when needed
Fix tags table view row height
Add country flags and spinner
Add HelperViewController

Add a helper view that explains how the app works.
Add tutorial with UIPageViewController

Added tutorial that explains how the app works