fix gemspec

Author: bogdanRada

README.md

@@ -13,7 +13,7 @@ Requirements
 3.	[jasmine >= 1.1](https://github.com/bogdanRada/celluloid_pubsub)
 4.	[nokogiri >= 1.6](https://github.com/swoop-inc/composable_state_machine)
 5.	[colorize >= 0.8](https://github.com/tj/terminal-table)
-6.	[coffee-script >= 2.4](https://github.com/fazibear/colorize)
+6.	[coffee-script >= 2.0](https://github.com/fazibear/colorize)
 
 Compatibility
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