should_validate_uniqueness_of remarkable_activerecord 4.0.0-alpha1

1) Customer 
    Failure/Error: should_validate_uniqueness_of :email    
    could not find a Customer record in the database
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable_activerecord-4.0.0.alpha1/lib/remarkable_activerecord/matchers/validate_uniqueness_of_matcher.rb:49:in `find_first_object?'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/dsl/assertions.rb:371:in `send'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/dsl/assertions.rb:371:in `send_methods_and_generate_message'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/dsl/assertions.rb:370:in `each'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/dsl/assertions.rb:370:in `send_methods_and_generate_message'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/dsl/assertions.rb:406:in `matches_collection_assertions?'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/base.rb:40:in `assert_collection'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/base.rb:39:in `each'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/base.rb:39:in `assert_collection'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/dsl/assertions.rb:404:in `matches_collection_assertions?'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/dsl/assertions.rb:291:in `matches?'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/macros.rb:28:in `send'
    # /Users/txus/.bundle/ruby/1.8/gems/remarkable-4.0.0.alpha1/lib/remarkable/macros.rb:28:in `should_or_should_not_method_missing'
    # /Library/Ruby/Gems/1.8/gems/polyglot-0.3.1/lib/polyglot.rb:64:in `inject'
    # ./spec/models/customer_spec.rb:15
    # ./spec/models/customer_spec.rb:3