Update README.md

Loosened the version requirement otherwise newcomers who copy and paste won't get the latest release :)

Author: brendon

README.md

@@ -22,12 +22,12 @@ u.last_seen  # => Mon Sep 22 17:28:38 +0200 2008
 
 ### Rails 3.2 - 4.2 / Ruby 1.9.3 and higher
 
-The current version of default_value_for (3.0.x) is compatible with Rails 3.2 or higher, and Ruby 1.9.3 and higher.
+The current version of default_value_for (3.x+) is compatible with Rails 3.2 or higher, and Ruby 1.9.3 and higher.
 
 Add it to your Gemfile:
 
 ```ruby
-gem "default_value_for", "~> 3.0.0"
+gem "default_value_for", "~> 3.0"
 ```
 
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