Configure output based on argument flags

Add "--tree" and "--graph" flags to control what gets printed to stdout.

Change-Id: I686e0966d2bf5e2daffbb5eea738036075f00288
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/build/drydock/+/2413147
3 files changed
tree: 827d9b5f2a2dcb7ed1cb85e69e5b9b1d2527567e
  1. src/
  2. .gitignore
  3. Cargo.toml