Sakia crash when publishing ID with utf8

Created by: galuel

Sakia crashes when clicking "publish ID" for a new ID : ğaluel

No information in the terminal.

uid could only be composed of ASCII characters: When trying publishing a new identity with ğ character, I get this message: 'ascii' codec can't encode character '\u011f' in position 4: ordinal not in range (128)'.

@c-geek : only ASCII, special character too ? (like, are chars ( ) [] - ... authorized ?)

It is not written explicitely in the protocol, however I only allow alphanumeric characters along with _ and -: https://github.com/ucoin-io/ucoin/blob/master/app/lib/constants.js#L6