Bump dependency on scientific
Add ToJSON and FromJSON instances for Scientific
Merge pull request #162 from basvandijk/master

Encode RealFloat numbers using Scientific.fromFloatDigits
Fix module sorting
Fix JSON instance for UTCTime

This fixes gh-158.
Ensure that arbitrary DiffTime values are millisecond-bounded
UTCTime roundtrip does not need approximate equality
Fix instance of ToJSON for ZonedTime