Version 0.8.0

This release adds two nice features to cargo-inspect:

• You can now choose different themes! Simply run cargo inspect --list-themes to get a list of available choices. For example, this will use the GitHub theme, which should work well on white backgrounds:
  cargo inspect examples/file.rs --theme GitHub
  [Thanks to @jonathansty]
• The output is now a bit cleaner, because formatting issues are now handled a little better. Even if rustfmt fails, we print the final output on a best-effort basis. Most of the time, this should look quite pleasing to the eye. If you want to see the full debug trace, you can use RUST_LOG=debug. [Thanks to @jonathansty]