Added test for unicode characters

There was an issue with utf8 encoded characters being badly encoded when
sent for verification of the authentication process. Now we've got a test for this.
Hopefully it's a good test.
Don't use uri_escape_utf8

For some reason uri_escape_utf8 - which was a fix for https://rt.cpan.org/Public/Bug/Display.html?id=67832
is now causing problems. Reverting to uri_escape seems to fix things.
v0.8.0

    Reverted use of uri_escape_utf8 back to uri_escape, I hope this doesn't cause problems for anyone.