Fixed issue 238 - Change DefaultDateTimeHumanizeStrategy to turn 60 min to one hour not 45, https://github.com/MehdiK/Humanizer/issues/238
Added "60 minutes" to return "an hour ago" for all locals.
Updates release_notes.md

updated release notes with [#278](https://github.com/MehdiK/Humanizer/pull/278): Added "60 minutes" to "an hour ago" test cases for all locals
Merge branch 'default-datetime-humanize'