rspec/rspec-rails — pull request #599 by jonhyman (2012-08-18 14:00:00+00:00)
Title: Checking for existence of ActiveRecord in proxy.rb before getting constants from it.

I'm using Mongoid and just got this error on HEAD due to this change. Projects that use Mongoid don't use ActiveRecord. This checks for ActiveRecord in the proxy.rb file. I tested on my project and it appears to fix the issue.

```ruby
/Users/jonathan/.rvm/gems/ruby-1.9.3-p194/bundler/gems/rspec-rails-fb55955687e2/lib/rspec/rails/extensions/active_record/proxy.rb:8:in `block (3 levels) in ': uninitialized constant ActiveRecord (NameError)
```