Use Pry from console instead of IRB in development

Since `pry` gets bundled by default, we should attempt to load it in the provided
`console` file. If the user has removed Pry or is for some reason in the production
environment, we can fall back to IRB.

Signed-off-by: David Celis <me@davidcel.is>
Merge pull request #42 from davidcelis/patch-1

Use Pry from console instead of IRB in development