Allow for a local installation of aglio

[alappe]

To use it locally:

npm install aglio in your project using blue_bird, then set aglio_path: "./node_modules/.bin/aglio in the config.

[woylie]

Thanks for the PR! Unfortunately, this doesn't work like it is, because the default value aglio is not a complete path to the binary and File.exists?/1 doesn't find it (see ci). Perhaps you could make a check on the :aglio_path first: If a value is set, use File.exists?/1, and if it is not set, try to find the globally installed executable with System.find_executable/1.

What do you think?

@rhazdon

[woylie]

Oh, and if you implement it that way, it would be great to have the error message reflect both ways.

[alappe]

Sure, I'll adapt it tomorrow. I was on the way to a meeting this morning and this was the minimal case I needed to make it work on my machine. So I thought I'd share for comments before I forget it at all ;-)