fix: middleware functions added in 'beforeAction' not executing

[zacharygolba]

This PR fixes the issue of middleware not being executed when added to the beforeAction array on a Controller.

The reason this bug exists is because #65 introduced many improvements where previously computed properties were moved to it's classes constructor in attempt to prevent multiple executions of a getter. The downside of doing this is that class properties will not be installed on the prototype until after the constructor is called. This simply moves the middleware property back to a computed getter function which is later memoized in the Route class upon the application's boot so there is no perf regression.

This PR also removes the parent class Base from Controller which is part of an ongoing refactor to no longer be using Base as a parent for packages within Lux. It doesn't provide any additional functionality since we can mimic setProps with Object.assign(this, props) and it will be better to not dirty the prototype chain moving forward unless it's absolutely necessary.

Closes #94

[jhliberty]

Reviewing the code.. can't assign myself but feel free to do it for me

[mutewinter]

looked good to me. I like the regression test