Rework specs to function under jruby
Merge pull request #41 from billdueber/jruby

Rework specs to function under jruby
closes #30
Move spec
Add group operation
Remove unneeded inclusion
Move defining in-memory relations to env#relations block
Move spec
Allow chaining with ra::group too
Add Relation#insert
Add Relation#update
Add Relation#delete
Fix grouping when there is more than 1 item to group
add map_to_model('ClassName', *attributes) to mapper builder
rename map_to_model into model
Merge pull request #51 from Olefine/mapping-model

Add automatic model class builder

refs #40
Improve mapper definition DSL and simplify Mapper itself

  * Change order in which env must be setup (mappers must be defined at the end)
  * Change mappers DSL to be more inline with relations DSL
  * Introduce `Env#reader` which allows reading relations and loads tuples
    using a mapper
  * Remove horrible `rom.relations.users(mapper: true/false)` interface
  * Change Mapper to simply consist of a header and model and add `Mapper#load`

refs #52
Update benchmark
Make it possible to read a grouped relation

refs #52
Extend model DSL

  * Make it possible to set model type
  * Default to all attributes if no :map option is provided

Refs #52
Let's make building POROs 2 x faster