Introduce Configuration

[dropdevcoding]

Currently we use protected methods to return the relevant middlewares adroit consists of and works on.
Due to this, you would have to inherit AdroitMiddleware to change that behavior / the used classes.
Imho the better approach would be to inject that middlewares by passing a Configuration instance to Adroit.

Configuration should:

• have a protected constructor
• provide a factory method Configuration::withDefaults() and which returns a Configuration with exactly the middlewares currently used by Adroit
• have immutable methods which return a new instance having defined the new middleware (e.g. $configuration->withActionExecutorMiddleware)
• should expose the current protected static attributes of adroit as public statics to enable reusage in own configuration since the constructors signatures may look different

Adroit then should:

• have a protected constructor
• only offer a factory method Adroit::create(Configuration $config = null)
• use $this->config = Configuration::withDefaults() no config is given