multiple .env args gets concatenated

[J-Zeitler]

When using an .env file with multiple args, such as:

A=aaaa
B=bbbb

that's later used in docker-compose.yml:

services:
  myservice:
    environment:
      - A=${A}
      - B=${B}

the args read by dcr gets concatenated and will result in something like:

$ echo $A
aaaa
B=bbbb

This behavior is not present when running normal docker-compose up ...

I guess the offending code is here somewhere:

https://github.com/modfin/dcr/blob/master/dcr.go#L381-L418