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 know that this is getting hairy, thanks for taking care of this. To build
a framework from scratch is never easy :)

What if we do a dangerous thing like this?

```ruby
before do
  @current_load_paths = $:.dup
  $:.clear
end

after do
  $:.push *@current_load_paths
end
```


On Thu, Jul 3, 2014 at 4:52 PM, David Celis <notifications@github.com>
wrote:

> In test/commands_console_test.rb:
>
> > +  let(:opts) { Hash.new }
> > +
> > +  before do
> > +    @console = Lotus::Commands::Console.new(opts)
> > +  end
> > +
> > +  describe '#options' do
> > +    it 'merges in default values' do
> > +      @console.options[:config].must_equal 'config.ru'
> > +    end
> > +  end
> > +
> > +  describe '#start' do
> > +    before do
> > +      @rack_builder = Minitest::Mock.new
> > +      @rack_builder.expect(:parse_file, true, ['config.ru'])
>
> Removing the constant won't cause require 'pry' to fail, unfortunately.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/lotus/lotus/pull/37/files#r14517643>.
>