Add dependency of ido-ubiquitous on ido-cr+

This can't be merged into master until MELPA merges the ido-cr+ recipe,
or else ido-ubiquitous will depend on a package that doesn't exist yet:
https://github.com/milkypostman/melpa/pull/2670

ido-ubiquitous.el

@@ -8,7 +8,7 @@
 ;; Created: 2011-09-01
 ;; Keywords: convenience, completion, ido
 ;; EmacsWiki: InteractivelyDoThings
-;; Package-Requires: ((emacs "24.1"))
+;; Package-Requires: ((emacs "24.1") (ido-completing-read+ "3.0"))
 ;; Filename: ido-ubiquitous.el
 
 ;; This file is NOT part of GNU Emacs.