Add application/vnd.api+json as a synonym for application/json

actionpack/lib/action_dispatch/http/mime_types.rb

@@ -47,7 +47,7 @@
 # https://www.ietf.org/rfc/rfc4627.txt
 # http://www.json.org/JSONRequest.html
 # https://www.ietf.org/rfc/rfc7807.txt
-Mime::Type.register "application/json", :json, %w( text/x-json application/jsonrequest application/problem+json )
+Mime::Type.register "application/json", :json, %w( text/x-json application/jsonrequest application/problem+json application/vnd.api+json )
 
 Mime::Type.register "application/pdf", :pdf, [], %w(pdf)
 Mime::Type.register "application/zip", :zip, [], %w(zip)