Swagger updates to pass validation (#696)
Swagger updates to pass validation (#696)

Make http://bigstickcarpet.com/swagger-parser/www/index.html happy:
* Add missing WorkspaceAccessLevel
* EntityQueryParameters -> EntityQuery
* give maps a type: object
* clean up executionEvents
* date-time
* int -> integer
* don't specify empty parameters
* description

broadinstitute/rawls,broadinstitute/rawls