Add support for umbrella project.

[seantanly]

Add support for phoenix under umbrella project.

Fixes issue #21

[bhserna]

Hi @seantanly, I am needing also a solution for the issue #21, but I can't make your fix to work for me =( ...

I am just adding a file phoenix_static_buildpack.config with...

phoenix_relative_path="apps/my_phoenix_web_app"

And watching the logs all goes well but when I visit the app in the web browser the assets are not there.

[seantanly]

Hi @bhserna, are you able to share on Github a stripped down version of your app so that I can take a look?

[bhserna]

@seantanly I upload a test app here https://github.com/bhserna/heroku-build-pack-test-case ... I removed all the application code, but is basically the same configuration.

Thanks for your help!

[seantanly]

@bhserna You might be simply missing the following in your apps/food_shop_web/mix.exs.

   def project do
     [app: :food_shop_web,
      version: "0.0.1",
+     build_path: "../../_build",
+     config_path: "../../config/config.exs",
      deps_path: "../../deps",
      lockfile: "../../mix.lock",

I have this version working on my Dokku deployment. https://github.com/seantanly/heroku-build-pack-test-case

Note that I'm pointing to my version of phoenix buildpack which contains the fix since this fix isn't merged into official master yet.

[bhserna]

@seantanly thanks!! your fix and those two lines make it work for me!!

[seantanly]

@bhserna you're welcome! Let's hope the fix gets merged into master soon. :) @gjaldon ;)

[gjaldon]

Thanks guys for testing this out! @seantanly @bhserna and thanks @seantanly for the PR! 👍