Deadlinks

* `feature` : new option `--skip-robots-checks` so robots.txt can be skipped
* minor testing changes.

* `docs` : bugfix in documentation.

* `feature`: 8 `robots.txt` supported (only checking what content allowed to be crawled)
* `feature`: github actions supported image (see 28)
* `docs`: github actions supported image (see 28)
* `bugfix`: 51 links with \n character are working now.
* `bugfix`: 46 trailing slash in redirection urls.
* `bugfix`: 33 external redirection error

* `docs`: Added AzurePilelines and CircleCI integration examples (https://deadlinks.readthedocs.io/).
* `bugfix`: Improved a bit local files checks (https://github.com/butuzov/deadlinks/issues/45).

* `docs`: better documentation with ci examples (https://deadlinks.readthedocs.io/).
* `install`: install `deadlinks` on mac with `brew` (https://github.com/butuzov/homebrew-deadlinks)
* `feature`: `_redirects` files support (https://github.com/butuzov/deadlinks/tree/0.2.0)
* `feature`: `serve` local files (https://github.com/butuzov/deadlinks/tree/0.2.0)

* `bugfix`: butuzov/deadlinks20 termination bug finally caught.
* `project`: TravisCI improved by fixing tests and implementing checks for the docs.
* `project`: Links in project at pypi.org.
* `fix`: butuzov/deadlinks4880db5 typo in Exception Class name fixed.