move oauth token response parsing to QLineParser

lib/instapaper/api/oauth.rb

@@ -1,3 +1,5 @@
+require 'instapaper/http/qline_parser'
+
 module Instapaper
   module API
     # Defines methods related to OAuth
@@ -5,10 +7,7 @@ module Instapaper
       # Gets an OAuth access token for a user.
       def token(username, password)
         response = perform_post_with_unparsed_response('/api/1/oauth/access_token', x_auth_username: username, x_auth_password: password, x_auth_mode: 'client_auth')
-        params = response.split('&')
-        values = params.map { |part| part.split('=') }.flatten
-        values.unshift('error') if values.length == 1
-        Hash[*values]
+        QLineParser.parse(response)
       end
     end
   end

lib/instapaper/http/qline_parser.rb

@@ -0,0 +1,9 @@
+module Instapaper
+  class QLineParser
+    def self.parse(response)
+      values = response.split('&').map { |part| part.split('=') }.flatten
+      values.unshift('error') if values.length == 1
+      Hash[*values]
+    end
+  end
+end