v0.9.8

Fixed

• Joining a URI path no longer builds a backend. 0.9.7 routed / and
  joinpath() through the child builder a listing uses, which reads the
  backend property -- and that property CREATES one, so spelling
  UriPath("sftp://h/x") / "y" imported paramiko and raised ImportError
  without the extra (http: wanted requests, s3: botocore). A join
  is a pure-path operation and is lazy again; a child still shares its
  parent's connection when one already exists, which is all the sharing was
  ever for.

Full Changelog: v0.9.7...v0.9.8