Automatically refresh tokens on 429 errors

[z1lc]

Toodledo will start returning 429's after 100 API calls for a given access token (see docs). However, you can refresh the access token using the regular "/account/token.php" API call to get another 100 API calls, up to 10x per hour. It would be nice if the library did this refresh automatically.

[rkhwaja]

That's great! I didn't realize that. The Travis CI is always failing for this reason because it has no way to store the new access token.

[z1lc]

Oh wow, thanks for implementing this!

[rkhwaja]

Turns out my fix didn't work and I'm not updating this project anymore. I'm just reopening this issue so that people know that the current code doesn't do this correctly.