Remove multidb module and extension in the doc (Codeception#168)

* Update modules.yml

* Update extensions.yml

Author: eXorus

_data/extensions.yml

@@ -27,10 +27,6 @@
   description: The reporter with a progress bar
   image: /images/extensions/codeception-progress-reporter.png  
 
-- name: MultiDb
-  link: http://github.com/redmatter/Codeception-MultiDb
-  description: Extension that enables working with multiple dabatase backends and safe switching between them. It provides equivalant service as the Db module and more. Use v1.x for codeception v2.0 and v2.x for codeception v2.1.
-
 - name: DrushDb
   link: http://github.com/pfaocle/DrushDb
   image: https://www.drupal.org/files/druplicon-small.png  

_data/modules.yml

@@ -114,10 +114,6 @@
   link: https://github.com/mendicm/css-regression
   description: CSS / Visual regression tests integrated in Codeception. This module can be used to compare the current representation of a website element with an expected based on a reference image. This module does not require any JavaScript injections in your website and works with viewport screenshots (chromedriver). Compatible with WebDriver and AngularJS modules.  
 
-- name: MultiDb
-  link: https://github.com/iamdevice/codeception-multidb
-  description: Extension or work with multiple databases and switch between them. Based on original Db module. Make for codeception v.2.2
-   
 - name: Mountebank
   link: https://github.com/meare/codeception-mountebank
   description: Stub and mck external services with mountebank