Angular Package Format and Ivy Compatibility

Project bootstrapped from scratch with Angular CLI and packed into Angular Package Format (APF) which means no compatibility issues with different versions of Angular (including Ivy) and different environments.

The source code of library cleaned up, aligned with modern code conventions and written using strict Typescript checks.

Closes: #61

Features

• ccDirective now implements `exportAs: 'ccDirective' and exports resolved card scheme which means you can use it in your templates for advanced styling or presentation purposes with no additional effort:

<input ccNumber #ccNumber="ccNumber">
<span class="scheme">{{ccNumber.resolvedScheme$ | async}}</span>
<!-- will print: unknown, visa, amex and etc -->

Closes: #45

BREAKING CHANGES

• exportable member CreditCardValidator changed to CreditCardValidators (with s at the end)