README.md in codily-0.1.0.beta vs README.md in codily-0.2.0

@@ -41,9 +41,11 @@
 codily --apply --file ./codily.rb
 codily --apply --file ./codily.rb --dry-run
 codily --apply --file ./codily.rb --target my-service
 ```
 
+You have to set api key in environment variable `FASTLY_API_KEY`
+
 ## Restrictions
 
 - Directors are not supported due to its deprecation
 
 ## DSL