Added blackjack card subclass

* aces default to 11
* face cards defaults to 11

fixed typo in readme
added a basic dealer
added codeclimate to readme
updated travis build info

made ci scripts exec

added travis build image to readme

fixed tests to use the class

* playing_cards/deck_test
* blackjack_cards/deck_test

Added basic rdoc on classes to get the build to pass

minor edit to readme [skip ci]

minor edit to readme [skip ci]
added blackjack deck build example to readme [skip ci]