Support changes in modules/ directories

[lkysow]

Fixes #188.

With this change, we'll detect changes in any directories under modules/. We'll then try to run plan one directory up from the modules/ dir.

Examples:

• change to modules/main.tf will run plan in .
• change to project/modules/main.tf will run plan in project/
• change to modules/dir/main.tf will run plan in .

The only issue with this would be if a modules dir was being used between multiple projects, ex.

project1/
- main.tf # this references ../modules
project2/
- main.tf
modules/
- module.tf

[lkysow]

@ntietz would this work for your use-case?

[lkysow]

I don't think we need _modules because it's not a common directory for modules. Googling for it shows only Hootsuite uses.

[ntietz]

@lkysow Yes, I think this will work for our use-case, assuming that it captures changes in, say, modules/dir/otherfile.tf, not just ..../main.tf. (I assume it does, based on the diff, but I am unfamiliar with both go and this codebase.)

[lkysow]

Okay awesome! I'll push a new release.

[lkysow]

Available in the latest release: https://github.com/hootsuite/atlantis/releases/tag/v0.2.1