Remove MemInfoDumpTask

## Description

MemInfoDumpTask requires https://github.com/BitOne/php-meminfo to run and this repository seems abandonned.

## Requirements

* Documentation updates
  - [X] Reference
  - [ ] Cookbooks
  - [X] Changelog
* [ ] Unit tests 

## Breaking changes

* \CleverAge\ProcessBundle\Task\Debug\MemInfoDumpTask has been deleted
