Support for string compilation using indented (SASS) string syntax.

[amcgregor]

Fixes #41.

[asottile]

Looks like your change fails flake8. Could you fix that and add a quick test?

Other than that,

[amcgregor]

Yup, noticed the flake8 failure… wow those Travis tests take a long time to complete. Updating now.

[amcgregor]

Should be good to go.

[asottile]

Thanks for the PR!

[amcgregor]

It never hurts to help. I may tackle the @import callback thing (#81) later, as it's needed at work. Do you have a release schedule for pypi published releases?

[asottile]

I usually release whenever someone asks or when I need a new release. Would you like me to cut a new version?

[amcgregor]

@asottile Ah, might wait until I've pushed the @import callback code, but after that for sure. That's a significant feature to add.

[asottile]

Sounds good to me, looking forward to reviewing :)