fix for issue #180
The api should be passed an object that supports .to_time. If it happens
to be something else, make a best effort to convert it to a time object (such
as if a string is passed in -- which happens in a few of the tests).
Failing conversion, the rescue stanza will result in an http 200
response, which should be a 'safe' thing to do.
Signed-off-by: Konstantin Haase <konstantin.mailinglists@googlemail.com>