Add model, controller and view for AAC decisions

Build models for AAC, import data

Rename subcategory id column in aac decisions table

Add date, ncn, category and parties to index view

Add AAC import errors table

Add AAC decisions document files

Add AAC import instructions to README. Fix import rake task. Add tests for doc processing.
Import for EAT judgments

Created a rake task & a model for it
Updated .gitignore in order to ignore 'data' dir
Imported EAT jurisdiction_level1 table data
Imported EAT jurisdiction_level2 table data
Imported EAT level2jury table data
Added EAT judgment_jurisdictions table

added the model relationships
added a rake task for the whole 'import:eat'
Added Rails ERD diagraming gem
Added EAT causelist table