account creation related

[FutureLearnSole]

case: if User enter a flashy username with character [.] > the SimpleID registrations fails without warning.

Only realize this upon multiple attempts and giving up to register through Blockstack Browser and stumbling upon their own username character range limits through their Create New ID >Check Availability

Invalid username (a-zA-Z0-9_)

No biggie, FutureLearnSole