Environment Variable support?

[rwaweber]

Thanks for building this!

Would you be open to a contribution expanding support for the username, password and url arguments as environment variables?
For our use case, it would simplify using mark in a continuous integration context.

Unfortunately it looks like docopt.go doesn't seem to support environment variables in its configuration: docopt/docopt.go#48

A cursory pass at the code looks like this might be a good spot for some of the os.Getenv calls.

[kovetskiy]

hi, it's actually implemented already, not documented tho
https://github.com/kovetskiy/mark/blob/master/config.go#L10-L12

[mrueg]

Environment variables are supported now.

[djpbessems]

Is there documentation on how to use Environment variables?

[mrueg]

https://github.com/kovetskiy/mark#usage see the variables in the brackets