Murray 3.0

[stefanomondino]

Murray ~> 2.0 is pretty stable and proven itself a useful tool for quick project bootstrap.

I'd like to reboot the whole project since it suffers from two main issues:

• Tests are far from simple to maintain and extend. Quick and Nimble are apparentely less and less used (way less than I originally imagined) and XCTest alone is powerful enough. Besides that, SPM finally introduced support for resource bundles, meaning that we can mock Murray scenarios (folders with files and demo projects) way more easily.
• Configuration is sometimes a hassle, mainly because I chose JSON as default config "language". YAML is way more powerful (as I've learned from XcodeGen :) ). It seems legit to move to YML as default, while retaining compatibility with JSON.
• CLI may be improved, with more commands and explanations
• Logs and error message are poor and not self-explaining. I'd love to rethink the whole CLI experience with colors and something that it's easy to read

3.0 reboot will follow same approach as 2.0 regarding file structure and naming, and will (try to) not have breaking changes.