Histograms statistic sets sending the wrong max, min, and sum values

[williedoran]

On logging several histograms to cloudwatch i was looking out for max values to match what i was seeing in my server logs. They were not the same. I investigated and looked at the stageMetricDatum method which is being used to convert both timer and histogram statistic sets. This method does a conversion by a factor depending on the time duration which makes sense for a timer but doesnt seem to make sense for max, min, sum over time as scaling by the duration shouldnt matter in this case. I added a simple test to show this, and a simple fix in the code base. I have a pull request to hopefully fix this if i understand the code correctly

[azagniotov]

Closing since it was addressed in: #6