Fixed typo

Author: uetchy

README.md

@@ -7,7 +7,7 @@ $ bundle install --path vendor/bundle --binstubs=.bundle/bin
 $ rake link
 ```
 
-If you using Alfred with Dropbox Sync folder, you should type `rake install` instead of 'rake link'.
+If you using Alfred with Dropbox Sync folder, you should type `rake install` instead of `rake link`.
 
 ## Thanks