Refactor strategies to remove .build(server)

These objects don't ever seem to be initialized outside of the .build
method, so we can simplify things and make them conform to a more 
consistent interface by allowing their initializers to take a server
instead of individual parameters.

lib/doorkeeper/request/authorization_code.rb

@@ -1,14 +1,10 @@
 module Doorkeeper
   module Request
     class AuthorizationCode
-      def self.build(server)
-        new(server.grant, server.client, server)
-      end
-
       attr_accessor :grant, :client, :server
 
-      def initialize(grant, client, server)
-        @grant, @client, @server = grant, client, server
+      def initialize(server)
+        @grant, @client, @server = server.grant, server.client, server
       end
 
       def request

lib/doorkeeper/request/client_credentials.rb

@@ -1,14 +1,10 @@
 module Doorkeeper
   module Request
     class ClientCredentials
-      def self.build(server)
-        new(server.client, server)
-      end
-
       attr_accessor :client, :server
 
-      def initialize(client, server)
-        @client, @server = client, server
+      def initialize(server)
+        @client, @server = server.client, server
       end
 
       def request

lib/doorkeeper/request/code.rb

@@ -1,14 +1,11 @@
 module Doorkeeper
   module Request
     class Code
-      def self.build(server)
-        new(server.context.send(:pre_auth), server)
-      end
-
       attr_accessor :pre_auth, :server
 
-      def initialize(pre_auth, server)
-        @pre_auth, @server = pre_auth, server
+      def initialize(server)
+        @pre_auth = server.context.send(:pre_auth)
+        @server = server
       end
 
       def request

lib/doorkeeper/request/password.rb

@@ -1,14 +1,12 @@
 module Doorkeeper
   module Request
     class Password
-      def self.build(server)
-        new(server.credentials, server.resource_owner, server)
-      end
-
       attr_accessor :credentials, :resource_owner, :server
 
-      def initialize(credentials, resource_owner, server)
-        @credentials, @resource_owner, @server = credentials, resource_owner, server
+      def initialize(server)
+        @credentials = server.credentials
+        @resource_owner = server.resource_owner
+        @server = server
       end
 
       def request

lib/doorkeeper/request/refresh_token.rb

@@ -1,14 +1,12 @@
 module Doorkeeper
   module Request
     class RefreshToken
-      def self.build(server)
-        new(server.current_refresh_token, server.credentials, server)
-      end
-
       attr_accessor :refresh_token, :credentials, :server
 
-      def initialize(refresh_token, credentials, server)
-        @refresh_token, @credentials, @server = refresh_token, credentials, server
+      def initialize(server)
+        @refresh_token = server.current_refresh_token
+        @credentials = server.credentials
+        @server = server
       end
 
       def request

lib/doorkeeper/request/token.rb

@@ -1,14 +1,11 @@
 module Doorkeeper
   module Request
     class Token
-      def self.build(server)
-        new(server.context.send(:pre_auth), server)
-      end
-
       attr_accessor :pre_auth, :server
 
-      def initialize(pre_auth, server)
-        @pre_auth, @server = pre_auth, server
+      def initialize(server)
+        @pre_auth = server.context.send(:pre_auth)
+        @server = server
       end
 
       def request

lib/doorkeeper/server.rb

@@ -8,12 +8,12 @@ def initialize(context = nil)
 
     def authorization_request(strategy)
       klass = Request.authorization_strategy strategy
-      klass.build self
+      klass.new self
     end
 
     def token_request(strategy)
       klass = Request.token_strategy strategy
-      klass.build self
+      klass.new self
     end
 
     # TODO: context should be the request

spec/lib/server_spec.rb

@@ -45,7 +45,7 @@
 
     it 'builds the request with selected strategy' do
       stub_const 'Doorkeeper::Request::Code', fake_class
-      expect(fake_class).to receive(:build).with(subject)
+      expect(fake_class).to receive(:new).with(subject)
       subject.authorization_request :code
     end
   end