Support proxying final implementations of interfaces

• Support proxying final implementations of interfaces
• Drops support for PHP 7 and switch to friendsofphp/proxy-manager-lts since development of ocramius/proxy-manager has halted.

Add PHP 8 support

Support PHP 8 besides 7.2+

Use more correct proxy method

This code initially used a lazy-load proxy method. That seemed to work fine, but turned out to be broken with the friendsofphp/proxy-manager-lts re-implementation of ocramius/proxy-manager.

This update also updated all code to use Laminas's code-generator rather than the abandoned version of Zend.

Make proxy method names more unique to prevent collisions

This release makes the proxy method names more unique to prevent collisions.

This changes the signature of the MockableService-methods, so change them accordingly:

• setAlternative() is now setAlternativeService()
• setOriginal() is now setOriginalService()
• reset() is now restoreOriginalService()

Note, this release also upgrades the minimum php version to 7.2

Loosen up ocramius/proxy-manager requirements

Merge pull request #1 from winkbrace/master

Loosen up ocramius/proxy-manager requirements and update phpunit