Maps to the aasm_column in the database. Deafults to "aasm_state". You can write:

  create_table :foos do |t|
    t.string :name
    t.string :aasm_state
  end

  class Foo < ActiveRecord::Base
    include AASM
  end

OR:

  create_table :foos do |t|
    t.string :name
    t.string :status
  end

  class Foo < ActiveRecord::Base
    include AASM
    aasm_column :status
  end

This method is both a getter and a setter