[PROPOSAL] Support a "ava.config.js" file to make config portable

[danawoodman]

Description

I propose that ava support a configuration file (e.g. ava.config.js) which is similar to the package.json configuration. This file would make it more obvious where configuration lives as well as making it more portable since the ava.config.jsfile could just be copied over to a new project; no editing of package.json needed. Plus, it's a bit of good marketing since people looking at the source of a project would notice the config file. Win-win-win.

There is a great package, cosmiconfig, which allows for both package.json config, ava.config.js and a .avarc file depending on the user's preferences. Prettier just added it and it makes adoption a lot easier for the end user.

Relevant Links

• cosmiconfig

[sindresorhus]

Duplicate of #520