DX meta issue

[wolfv]

rattler-build is fast, that's nice! But the CLI isn't as sharp as it could be. Here is a list of issues from the top of my head:

• rattler-build build is annoying to type. Can we make build the default?
• --recipe is maybe annoying, should we just take the recipe file as positional arg?
• same goes for rebuild --package-file and test --package-file

@baszalmstra thinks that the output is not as great as it could be and it's true. We should figure out how to clearly structure the output to show the user what's happening when and why. I don't have super concrete things there yet, though.