It appears that in order to get any use from the GatewayClient.env_whitelist and the EnterpriseGatewayApp.env_whitelist options, their values have to match. This is made somewhat awkward by the fact that the GatewayClient.env_whitelist option is backed by a unicode traitlet (and is meant to be a comma separated string of values) and the EnterpriseGatewayApp.env_whitelist is a proper list traitlet. These should match, so one of these should change.

@kevin-bates I can submit the PR for this. Should I change EnterpriseGatewayApp.env_whitelist to a unicode traitlet, or vice versa?