Add a simple `lotus console` command

`lotus console` will spawn an IRB (or Pry, if bundled) session that
loads the application code. This is a very basic analogue to `rails
console` and would be nice for testing out code ideas or modifying the
database.

Signed-off-by: David Celis <me@davidcel.is>
I can't get this working locally and don't see how it would work anywhere. When running `lotus console` I get an error which indicates that IRB is trying to load "console".

If you look at https://github.com/ruby/ruby/blob/trunk/lib/irb/init.rb#L128 you'll see that IRB will attempt to parse ARGV. I'd suggest cleaning ARGV in `Lotus::Cli` class so we don't get these issues.