v0.17.0

• BREAKING CHANGE: Remarshal no longer turns boolean and null keys into strings by default when converting to JSON. The default is to exit with an error. The previous default could cause silent data corruption, for example, when converting a GitHub Actions workflow file with an unquoted on key from YAML to JSON. While this is a breaking change, it should not affect most users.
• The new flag -k/--stringify restores the old JSON conversion behavior of turning boolean and null keys into strings. Additionally, it turns date-time keys into strings and works for both JSON and TOML. it also converts null values to strings for TOML, since TOML does not have null.