Feature/improved login experience

Code has not yet been tested

Adds a login command that can be used to update credentials without having to go through all settings
Automatically checks token expiry and prompts to re-login if it's expired
When running raisely start will prompt to re-login if token expires soon so it doesn't go unnoticed and cause confusion during development
Checks organisationUuid against the token to fail fast if user account has been switched out
Offers to switch a user back to the correct org if they are switched out

Fixes raisely/raisely#1126

raisely / cli