Add Pry support for Pliny

As discussed in #98, let's pull Pry in instead of standard IRB. It's
very useful as a console in development and production, and also hugely
useful for debugging in development and testing. It also seems to be
fairly well standardized in that many projects want to see its
inclusion.

Fixes #98.
move Initializer.root to Config.root
Merge pull request #119 from interagent/pedro-config-root

move Initializer.root to Config.root
Pull in Shogun's prompt customization
Merge pull request #118 from interagent/brandur-pry

Add Pry support for Pliny
dump updated schema
dump schema again with the latest pliny task so comments are gone
Render Pliny errors from block in base endpoint
Merge pull request #124 from interagent/brandur-render-errors

Render errors from within base endpoint
Merge pull request #123 from interagent/pedro-schema-dump-tweaks

Tweak dumped schema
Allow serializers to take arrays

At the moment serialization only allows individual objects to be serialized.
Arrays of objects need to be `map`'ed in the endpoint.  This commit changes that
so serialize can take one or many objects of a given type and sort it out so the
endpoint doesn't need to.
Merge pull request #125 from neilmiddleton/better_serializer

Allow serializers to take arrays