More bug fixes

Fixing this issue:

#121

Bug fixes

Fixed a bug with email addresses in mailto hrefs not being detected and the metadata output file not being created when it should.

Max Length

Allow the user to specify the max word length as well as the minimum.

Syncing version numbers

No code changes, but it was pointed out that the version number between GitHub and the code had got out of sync so fixing it.

New Nokogiri

Nokogiri had a vuln, this fixes it.

Updated minimum gem versions

Update the minimum version of mime-types and nokogiri gems.

Concat Fix

Fixed a problem with accidental concatenation of words when stripping HTML tags.

Docker

Added Docker support

Nokogiri version bump

Updating the version of Nokogiri due to upstream security issue.

Inclusion

Up to now, the content was only scraped from pages which returned with a success code (200's and similar), it is now scraped from every page, including error pages, 404's and redirects.