Updated README and updated composer deps a bit to reflect changes. (P…

…Cextreme#13)

* Updated README and updated composer deps a bit to reflect changes.

* Updated coveralls

Removed unused code

Added support for detail arrays in queries

Updated cache list on CS 4.10

Added support for Symfony 4.x, and updated API list. Resolves PCextre…

…me#2

Updated API list to support CS 4.10

Fixed double signing of client URL

Added client URL helper

Fixed consoleUrl helper

Update README