Allow sanitize version 2.0.x

Instead of requiring 2.0.3.

Sanitize sees id's with colons in 'a' tag hrefs (eg. <a href="#namespace:id">) as being links with protocols.  A pull request has been submitted to sanitize to fix this, but won't be released until version 2.1. A fork has been made with this fix cherry-picked onto sanitize 2.0.6.  This change makes that fork useable when govspeak is included.