Feature/metrics-timeresolution-support

Test cases for having Time series table with resolution for a minute and bug fixes to support that.

Time series table previously just writes the new data as we only tested resolution with a second, with minute aggregation , we would want to add to the previous timestamp if an entry exists and the metric type is counter, so added increment support in the time series table.

https://issues.cask.co/browse/CDAP-625
Please also add a javadoc.  "Save" is not descriptive enough as we can tell from this discussion.