Remove the PropositionAccepting abstraction

app/models/concerns/proposition_accepting.rb

@@ -1,7 +0,0 @@
-module PropositionAccepting
-  extend ActiveSupport::Concern
-
-  included do
-    has_many :propositions, as: :proposition_accepting
-  end
-end

app/models/proposition.rb

@@ -1,6 +1,5 @@
 class Proposition < ActiveRecord::Base
   belongs_to :proposer, class_name: 'User'
-  belongs_to :proposition_accepting, polymorphic: true
   belongs_to :proposable, polymorphic: true
 
   enum status: [:undecided, :approved, :rejected, :backup]

app/models/track.rb

@@ -1,6 +1,4 @@
 class Track < ActiveRecord::Base
-  include PropositionAccepting
-
   belongs_to :conference
   has_many :events
 

db/migrate/20150814204500_remove_proposition_accepting_fields_from_propositions.rb

@@ -0,0 +1,5 @@
+class RemovePropositionAcceptingFieldsFromPropositions < ActiveRecord::Migration
+  def change
+    remove_reference :propositions, :proposition_accepting, index: true, foreign_key: true, polymorphic: true
+  end
+end

spec/factories/propositions.rb

@@ -1,7 +1,6 @@
 FactoryGirl.define do
   factory :proposition do
     association :proposer, factory: :user
-    association :proposition_accepting, factory: :track
     association :proposable, factory: :event
   end
 end

spec/models/proposition_spec.rb

@@ -6,16 +6,10 @@ RSpec.describe Proposition, type: :model do
     expect(create(:proposition, proposer: user).proposer).to eq user
   end
 
-  it 'belongs to a proposition_accepting' do
-    track = create :track
-    expect(create(:proposition, proposition_accepting: track).proposition_accepting).to eq track
-  end
-
   it 'belongs to a proposable' do
     event = create :event
     expect(create(:proposition, proposable: event).proposable).to eq event
   end
 
-  it 'is invalid without an existing proposition_accepting'
   it 'is invalid without an existing proposable'
 end