Crates.io release 0.2.1

This is a Crates.io release of `irc-bot`, version 0.2.1. At this
point, the library is unfinished, unpolished, and unstable, but
usable.

Changes made since the previous release include some bug-fixes, one of
which is more of a feature-addition: one now can specify channels for
the example bot to join in its configuration file.

Crates.io release 0.2.0

This is a Crates.io release of `irc-bot`, version 0.2.0. At this
point, the library is unfinished, unpolished, and unstable, but
usable.

I don't think the library deserves a release at this point, but it's
much better than what I had on Crates.io before.

Crates.io release 0.1.0

This is the initial Crates.io release of `irc-bot`, version 0.1.0.
This version of the library is very basic and incomplete.