Merge pull request #83 from catalyst/issue81

issue #81: add user role condition

Author: dmitriim

README.md

@@ -63,6 +63,7 @@ Conditions are simple predicates which assert something about a user in the syst
 * User created time (time since a user was created).
 * User standard profile fields (e.g. first name, last name, username, auth method and etc).
 * User custom profile fields (text and menu types are supported).
+* User role (if a user has a role in a given context)
 
 ## Rules