[20190126182547] Prepare for CustomTopic Removal

This release prepares the Rack for the removal of the custom Lambda CloudFormation handler.

  • #3093 prepare for custom topic removal [@ddollar]
  • #3100 autoscaler needs api-level permission to cascade to stack update [@ddollar]

Turns out this is a required update version. You must update to this version first before updating to any version past this one.