Bugfix for issue #4

Fixed issue #4
Thanks to @JiankangMai.

Allow installation of codeception > 2.1

• Modified composer
• Tested codeception 2.2

Fixed version for http-mock in composer

• Changed http-mock version from dev-master to ~0.7
• Cleaning all configurations after each test.

First functional version

• Added module and extension with basic configuration.
• The module allows to build requests mocks.