[Core] Remove configuration (fixes #18).
[Core] Remove import.
[Core] Store all visited url in a json file (fixes #20).
Merge pull request #20 from novapost/20-save_visited_url

Save visited url.
Merge pull request #18 from novapost/18-remove_file

Remove configuration file.
[Core] Support json and yaml format (fixes #24).
[Core] Add a little doc.
[Core] Adding supported format in the error message.
[Core] Add support of a filename.
Merge pull request #24 from novapost/24-support_multiple_format

Multiple output format.
[Core] Add command line option to manage start url and allowed domain
(fixes #22).
Merge pull request #22 from novapost/22-command_line_option

Add (a) command line option(s) for the allow_domains and start_urls
[Core] The configuration file is not required but check if start url and
allowed domain is present (fixes #25).
[Documentation] Adding documentation (fixes #26).
[Documentation] Typo.
[Core] Typo.
[Core] Typo.
Merge pull request #25 from novapost/25-not_required

Configuration file is not required.
additional documentation
Merge pull request #26 from novapost/26-begin_documentation

Add documentation.