0.19.1

• avoid reflection fixes by Michael Blume
• one can now wrap body & response-models in predicates and get the swagger docs out:

  :return (s/maybe User)
  :responses {200 (s/maybe User)
              400 (s/either Cat Dog)}

• updated deps:

[metosin/ring-swagger "0.19.2"] is available but we use "0.19.1"