message: Use fixed v0.16.0-alpha2 image
diff: # Choose from https://hub.docker.com/r/cosmwasm/wasmd/tags
  REPOSITORY="cosmwasm/wasmd"
  -# TODO: update to (to be released) v0.16.0-beta1 before merge
  -VERSION="latest"
  +VERSION="v0.16.0-alpha2"
  CONTAINER_NAME="wasmd"
  