Fix typo in README

README.rdoc

@@ -134,7 +134,7 @@ The behavior of the association method varies depending on the build strategy us
 Because this pattern is so common, a prettier syntax is available for defining
 associations:
 
-  # The following definitions are equivilent:
+  # The following definitions are equivalent:
   Factory.define :post do |p|
     p.author {|a| a.association(:user) }
   end