Pyanchor

Changelog:

- Fixed issue where sitemaps URLs didn't always work with v0.2 results dictionary structure. Including tracking and printing totals.
- Successful links will not be printed to the terminal by default. Added a --verbose flag for printing all results.
- Fixed issue where an `Exception` is thrown and the cli fails when no URL produced a `200` response.

- Restructured the returning results dictionary. The `key` is now the HTTP response code, and the `value` is a list of all links that achieved that response code. This allows for faster and simpler searching for links with a particular HTTP response.

- Added total broken links to the printed output in the CLI.

- Flask web app added to the `tests/` folder for testing purposes.