Monitor uptime of corobo

First steps:
1. Maintain two vars `no_of_messages_received` and `no_of_messages_sent`.
2. Assert that `no_of_messages_sent` > `no_of_messages_received`

This gives a vague indication whether the bot is working clearly or not.

Next steps:
1. Log messages received and reply sent for those messages in a db for better debugging

Locate the bot's message-receive and reply paths, then identify where the two counters can be maintained. Inspect the existing database setup before implementing message logging; done means the sent/received check provides an uptime signal and received messages plus replies are persisted for debugging.

Written by the indexing model from the issue text.