Builds upon PR #28 to make use of custom exceptions module.
The challenge status is checked every 3 secs for a maximum of 30 secs. If it is still 'pending' after 30 secs, a custom error is raised.
If anyone has a source for how long LetsEncrypt might take to verify a challenge, that would be handy, but otherwise this default of 30s seems reasonable.
Builds upon PR #28 to make use of custom exceptions module. The challenge status is checked every 3 secs for a maximum of 30 secs. If it is still 'pending' after 30 secs, a custom error is raised.
Addresses issue #6.