Remove protected_attributes dependency

The protected_attributes gem and strong parameters in Rails 4 don't
play nice together in the same project: protected_attributes
completely takes over the mass assignment sanitization. Since it's
unlikely that transactions will be created from the form parameters
in the first place, this gem does not provide a real benefit.

Gemfile.lock

@@ -2,7 +2,6 @@ PATH
   remote: .
   specs:
     plutus (0.7.4)
-      protected_attributes (~> 1.0)
       rails (>= 3.1, < 4.1)
 
 GEM
@@ -51,8 +50,6 @@ GEM
     minitest (4.7.5)
     multi_json (1.7.9)
     polyglot (0.3.3)
-    protected_attributes (1.0.3)
-      activemodel (>= 4.0.0, < 5.0)
     rack (1.5.2)
     rack-test (0.6.2)
       rack (>= 1.0)

app/models/plutus/account.rb

@@ -30,8 +30,6 @@ module Plutus
   #
   # @author Michael Bulat
   class Account < ActiveRecord::Base
-    attr_accessible :name, :contra
-
     has_many :credit_amounts, :extend => AmountsExtension
     has_many :debit_amounts, :extend => AmountsExtension
     has_many :credit_transactions, :through => :credit_amounts, :source => :transaction

app/models/plutus/amount.rb

@@ -6,8 +6,6 @@ module Plutus
   #
   # @author Michael Bulat
   class Amount < ActiveRecord::Base
-    attr_accessible :account, :amount, :transaction
-
     belongs_to :transaction
     belongs_to :account
 

app/models/plutus/transaction.rb

@@ -22,8 +22,6 @@ module Plutus
   #
   # @author Michael Bulat
   class Transaction < ActiveRecord::Base
-    attr_accessible :description, :commercial_document
-
     belongs_to :commercial_document, :polymorphic => true
     has_many :credit_amounts, :extend => AmountsExtension
     has_many :debit_amounts, :extend => AmountsExtension

lib/plutus.rb

@@ -1,6 +1,6 @@
 # Plutus
 require "rails"
-require "protected_attributes"
+
 module Plutus
   class Engine < Rails::Engine
     isolate_namespace Plutus

plutus.gemspec

@@ -20,7 +20,6 @@ Gem::Specification.new do |s|
     "README.markdown"
   ]
   s.add_dependency("rails", ">= 3.1", '< 4.1')
-  s.add_dependency("protected_attributes", "~> 1.0")
   s.add_development_dependency("sqlite3")
   s.add_development_dependency("rspec", "~> 2.6")
   s.add_development_dependency("rspec-rails", "~> 2.6")