Heroku logs be like
2018-07-16T00:05:06.883023+00:00 app[bot.1]: Ready!
2018-07-16T00:05:11.940150+00:00 app[bot.1]: (node:4) UnhandledPromiseRejectionWarning: Error: 410 Gone
2018-07-16T00:05:11.940171+00:00 app[bot.1]: at _response.transport.request.then (/app/node_modules/snekfetch/src/index.js:193:21)
2018-07-16T00:05:11.940173+00:00 app[bot.1]: at <anonymous>
2018-07-16T00:05:11.940175+00:00 app[bot.1]: at process._tickCallback (internal/process/next_tick.js:188:7)
2018-07-16T00:05:11.940248+00:00 app[bot.1]: (node:4) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated
either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)
2018-07-16T00:05:11.940340+00:00 app[bot.1]: (node:4) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.