- set flag name to `--exit-code-from` (and rename some variable,
function and test names to match)
- force cascade_stop to true when exit-code-from flag is set
- use lambda in filter statement
- check that selected container name is in the project before running
- remove fancy parsing of service name to container mappings: if there
are multiple containers in a service, return the first nonzero exit
value if any
- flake8 changes
Signed-off-by: Nathan J. Mehl <n@climate.com>