Fix rails error regarding active_support not being required.

Author: Jonathan Wenger

lib/avatax/api.rb

@@ -1,5 +1,6 @@
 require File.expand_path('../connection', __FILE__)
 require File.expand_path('../request', __FILE__)
+require 'active_support'
 require 'active_support/notifications'
 require 'logger'
 

spec/spec_helper.rb

@@ -1,6 +1,5 @@
 require File.expand_path('../../lib/avatax', __FILE__)
 require 'rspec'
-require 'active_support'
 require 'yaml'