First pass at IIIF translation
More IIIF validation and tests
Add equivalent-xml as a development dependency for xml testing
Djatoka::Metadata can output IIIF Info Request xml/json
Ignore .ruby-version and .ruby-gemset
README and gemspec update with IIIF features
Add resolver convenience methods that work with Iiif params
Move requires to lib/djatoka.rb.  Rdoc cleanup