Set RACK_ENV before requiring files in spec_helper.rb

This is because liquor_cabinet.rb is using the
environment to read the appropriate configuration
settings.

spec/spec_helper.rb

@@ -1,3 +1,5 @@
+ENV["RACK_ENV"] = "test"
+
 require 'rubygems'
 require 'bundler'
 Bundler.require
@@ -8,8 +10,6 @@ require 'rack/test'
 require 'purdytest'
 require 'riak'
 
-ENV["RACK_ENV"] = "test"
-
 def app
   LiquorCabinet
 end