Swi restructure project (#26)

* Restructure files according to default swift package folder structure

example-package-playingcard
├── Sources
│   └── PlayingCard
│       ├── PlayingCard.swift
│       ├── Rank.swift
│       └── Suit.swift
└── Package.swift

* fix unit tests

* update Combine and Reactive Example

* update Github example

* remove old example folder

* Remove carthage compatibility from readme.

Co-authored-by: Matthias Buchetics <mbuchetics@gmail.com>

Author: wieweb