Old Dogs New Tricks (v0.1.0)

This release fixes all compatibility issues reported in the last 6 years:

• Slashes in document and database IDs are now URL-encoded properly.
• The type of the Seq field of DBUpdatesFeed and ChangesFeed is now interface{}.
  This makes go-couchdb compatible with CouchDB 2.0 and beyond.
• ChangesFeed now handles the include_docs option properly and populates the Doc field.
• The Content-Type HTTP header is now set for all requests containing an entity (i.e. POST and PUT requests).
• go-couchdb is now a Go module.