Switch to little-endian dates in CHANGELOG
Switch to little-endian dates in CHANGELOG

Little endian dates are [much more common][0] across the globe, whereas
big-endian ones are almost only used in the USA.

[0]: https://en.wikipedia.org/wiki/Date_format_by_country

Signed-off-by: Lorenzo Manacorda <86995a091f8a1385082bd10715048b52ee386a6a@kinvolk.io>

kinvolk/habitat-operator,kinvolk/habitat-operator