Updated AnimalMakerFactory (Ninject DI container)

Updated AnimalMakerFactory
- Expose one public static method to instantiate an entity.
- Ninject kernal made to be a private static field and get configured at
the static constructor
- Ninject bindings moved to a separate class where the kernel will load
in the factory's constructor.
- Removed the Ninject Nuget package from the Test project as all Ninject
functionalities moved to the Factory

Other changes
-Renamed IMaker to IAnimalMaker