Downgrade 'space-unary-ops' to warning because of bug
Downgrade 'space-unary-ops' to warning because of bug

A bug with 'space-unary-ops' was causing errors to be raised after we
updated to 0.23.0. This bug has since been resolved[1], so until that
bug fix is released we are downgrading this linter to a warning.

[1]: https://github.com/eslint/eslint/issues/2764

staltz/eslint-config-brigade,brigade/eslint-config-brigade