Reads errors on decimal durations

[nrktkt]

Currently parsing a duration doesn't support decimal numbers. This might be improved by a) rounding the input to the nearest whole number or b) dynamically changing the temporal unit based on presence of a decimal (ie. 123.45ms becomes 123450000ns).

Happy to open a PR if a or b are agreeable behaviors.

Play JSON Version 2.8.1

API Scala

Expected Behavior

Please describe the expected behavior of the issue, starting from the first action.

parsing a decimal JSON number into a Duration succeeds

Actual Behavior

parsing a decimal JSON number returns an error stating that a long is expected.