feature: redirects

[lordlabuckdas]

Major changes

Pages can now redirect, similar to the actual website.

meta.json structure:

{
    "/":
        {
            "redirect": "/new/home/"
        },
    "/new/home/":
        {
            "hash": "fb4b89f45c474f455a089130db94b00a",
            "headers": [{"Content-Type": "text/html"}]
        }
}

Minor changes

• Replaced counter with len(visited_urls)
• Transfer-Encoding header has been added to the ignore list

[mzfr]

@afeena The changes look good to me. If @lordlabuckdas isn't adding anything else to this PR then I think we can merge this.