0.2.1

• Added support for dplyr mutate_at/_if/_all and summarize_at/_if/_all for
  srvyr surveys.

• Fixed a few bugs introduced with dplyr 0.6. This version of srvyr will work
  with both old versions of dplyr and 0.6, but may be full of warnings if you
  update dplyr. Full support for the new dplyr is coming soon.