ade enter swallows exit code of command

Current behavior

When running a command inside ADE using ade enter -- cmd, the exit code of cmd is ignored

Expected behavior

• Either the exit code is forwarded to the host OR
• Documentation on why ade enter needs to swallow the exit code

How to reproduce

$ ade start
$ ade enter -- false
$ echo $?
0  # Expected 1

• We explicitly don't check the exit code: https://gitlab.com/ApexAI/ade-cli/blob/master/ade_cli/docker.py#L52