Don't raise a NoMethod error for attributes with a falsy value.

Fixes a problem with the Attributes mixin where an attribute set with a falsy
value such as false or nil, the model would not respond to the attribute
reader.

README.md

@@ -31,4 +31,5 @@ The easiest way to install Broach and its dependencies is to install the gem.
 
 Eloy Duran <eloy@fngtps.com>
 Ilya Sabanin <ilya.sabanin@gmail.com>
-Todd Eichel <todd@toddeichel.com>
+Todd Eichel <todd@toddeichel.com>
+Anton Mironov <ant.mironov@gmail.com>

lib/broach/attributes.rb

@@ -8,8 +8,8 @@ def initialize(attributes)
     def id; @attributes['id']; end
 
     def method_missing(method, *arguments, &block)
-      if value = @attributes[method.to_s]
-        value
+      if key = method.to_s and @attributes.has_key?(key)
+        @attributes[key]
       else
         super
       end

test/unit/attributes_test.rb

@@ -0,0 +1,23 @@
+require File.expand_path('../../start', __FILE__)
+
+class Mole
+  include Broach::Attributes
+end
+
+describe "A class with Attributes" do
+  before do
+    @mole = Mole.new('name' => "Jerry", 'glasses' => false, 'description' => nil)
+  end
+
+  it "returns it's attribute through accessor methods" do
+    @mole.name.should == "Jerry"
+    @mole.glasses.should.be.false
+    @mole.description.should.be.nil
+  end
+
+  it "does not respond to methods for attributes which haven't been set" do
+    lambda {
+      @mole.unknown
+    }.should.raise(NoMethodError)
+  end
+end