pull in latest arel

Gemfile

@@ -70,6 +70,7 @@ end
 gem 'seed-fu', '~> 2.3.3'
 
 if rails_master?
+  gem 'arel', git: 'https://github.com/rails/arel.git'
   gem 'rails', git: 'https://github.com/rails/rails.git'
 else
   gem 'rails'

Gemfile_master.lock

@@ -6,6 +6,12 @@ GIT
     active_model_serializers (0.8.2)
       activemodel (>= 3.0)
 
+GIT
+  remote: https://github.com/rails/arel.git
+  revision: 5035526b534a5d7c9d95eb6b66ade349c3a947f0
+  specs:
+    arel (6.0.0.beta2)
+
 GIT
   remote: https://github.com/rails/rails.git
   revision: 46f172798e56ba5383ba5305e2cce5aad02e8e30
@@ -86,7 +92,6 @@ GEM
     annotate (2.6.5)
       activerecord (>= 2.3.0)
       rake (>= 0.8.7)
-    arel (6.0.0.beta2)
     barber (0.4.2)
       ember-source
       execjs
@@ -446,6 +451,7 @@ DEPENDENCIES
   actionpack-action_caching
   active_model_serializers!
   annotate
+  arel!
   barber
   better_errors
   binding_of_caller