Persistent storage

[fczuardi]

For commands that requires some kind of memory, like #1 a way of dinamically addning new info to the bot's memory is important.

This issue is about adding some persistent storage, either a simple filesystem based or nice db (level or flumedb maybe)

[fczuardi]

hmm, if we are deploying it with now.sh, having the data on the same server as the bot wont work, we would have to keep a backup somewhere else to keep the data between deploys...

backing up on Dat would be cool...