Your requirements could not be resolved to an installable set of packages.
Problem 1
The requested package ckeditor/ckeditor (locked at 4.8.0, required as 4.7.3) is satisfiable by ckeditor/ckeditor[4.8.0] but these conflict with your requirements or minimum-stability.
Installation failed, reverting ./composer.json to its original content.
What to do about this error amigos?
Your requirements could not be resolved to an installable set of packages. Problem 1