Race condition running docker-compose

[avantgardnerio]

Describe the bug

When Ian ran docker-compose up --build, he ran into several errors:

[ballista-executor_1   | Error: Could not connect to scheduler
[ballista-executor_1   | 
[ballista-executor_1   | Caused by:
[ballista-executor_1   |     0: transport error
[ballista-executor_1   |     1: error trying to connect: tcp connect error: Connection refused (os error 111)
[ballista-executor_1   |     2: tcp connect error: Connection refused (os error 111)
[ballista-executor_1   |     3: Connection refused (os error 111)

and

[ballista-client_1     | /bin/sh: 0: cannot open sleep: No such file

and

[ballista-scheduler_1  | Starting nginx to serve Ballista Scheduler web UI on port 80
[ballista-scheduler_1  | nohup: failed to run command 'nginx': No such file or directory

We should fix these issues.

To Reproduce

Run the above command.

Expected behavior

A working docker composition.