Added all php file headers

* Also fixed some php-cs
* Fixed test file namespace
New features for elcodi:v0.1.7

* Added currency switcher, with all products and coupons with currency
* Added coupon-add and coupon-remove
* Cart view with coupons
* Order view with coupons
Merge pull request #7 from elcodi/feature/currency-switcher-coupons

Feature/currency switcher coupons