Don't automatically add id to all settings models

It doesn't really make sense for "singleton" models like Campfire global
settings, it's better to declare id everywhere when we need it.

Author: drogus

lib/travis/model/repository/settings.rb

@@ -6,6 +6,7 @@
 
 class Repository::Settings < Travis::Settings
   class SshKey < Travis::Settings::Model
+    attribute :id, String
     attribute :name, String
     attribute :content, Travis::Settings::EncryptedValue
 
@@ -17,6 +18,7 @@ class SshKeys < Collection
   end
 
   class EnvVar < Travis::Settings::Model
+    attribute :id, String
     attribute :name, String
     attribute :value, Travis::Settings::EncryptedValue
     attribute :public, Boolean, default: false
@@ -28,12 +30,9 @@ class EnvVars < Collection
     model EnvVar
   end
 
-
-
   attribute :ssh_keys, SshKeys.for_virtus
   attribute :env_vars, EnvVars.for_virtus
 
-
   attribute :builds_only_with_travis_yml, Boolean, default: false
   attribute :build_pushes, Boolean, default: true
   attribute :build_pull_requests, Boolean, default: true

lib/travis/settings/model.rb

@@ -9,8 +9,6 @@ class Model
     include ActiveModel::Validations
     include ActiveModel::Serialization
 
-    attribute :id, String
-
     class Errors < ActiveModel::Errors
       # Default behavior of Errors in Active Model is to
       # translate symbolized message into full text message,

spec/travis/settings/collection_spec.rb

@@ -7,6 +7,7 @@
     @model_class = Class.new(Travis::Settings::Model) {
       attribute :description
 
+      attribute :id, String
       attribute :secret, Travis::Settings::EncryptedValue
     }
 

spec/travis/settings/model_spec.rb

@@ -87,11 +87,6 @@ def name
     model.name.should == 'PIOTR'
   end
 
-  it 'automatically generates id attribute' do
-    model = model_class.new(id: 'foobar')
-    model.id.should == 'foobar'
-  end
-
   it 'handles validations' do
     model_class = Class.new(described_class) do
       attribute :name

spec/travis/settings_spec.rb

@@ -90,6 +90,7 @@
   describe 'to_hash' do
     it 'returns registered collections and all attributes' do
       model_class = Class.new(Travis::Settings::Model) {
+        attribute :id, String
         attribute :name, String
         attribute :content, Travis::Settings::EncryptedValue
       }