support a debug mode

[Nicholas Bransby-Williams]

where you catch exceptions and convert them to string and send them  as messages to user

save me doing:

module.exports = builder(message, apiRequest) => {
    try {
      //bot code here
    } catch(error) {
        return String(error);
    }
})

[Gojko Adzic]

Hi,

we use issues on github only for bugs. everything else should go to the gitter channel. You're more than welcome to submit a PR if you like for this, but if you want to just ask for a new feature and chat about it, please do it on the chat.