remove example rails app

* I'm not keen on mounting this inside my main rails app, I'd rather
  run it in a dedicated process
whitespace
remove action_controller integration
remove unused tests
remove Guardfile and unused gems
remove web socket app code

* I may bring it back, just paring things back to the basics to clear my
  head
remove json type for now

* I'll probably bring it back, just pruning back to the basics to begin
  with
remove load path shenanigans
remove logger
remove version constants

* They're rarely useful
update Gemfile.lock to remove gems
start work on a new Document class
add Document#version
Document can have operations applied to it
for new, Document#apply_op should bail on stale version
add Document#value
minor spec refactor
convert Text type from a module to a class

* just a personal preference, I prefer classes over ruby module
  shenanigans
Document should use Types::Text to process operations
initialize the doc type in the constructor