[BERT](http://bert-rpc.org/) specifies time in microseconds. Both [encoder](https://github.com/stephenjudkins/scala-bert/blob/05c30cc5c1f84747d1c90cb4c1c53f821350de8a/src/main/scala/Decode.scala#L40) and [decoder](https://github.com/stephenjudkins/scala-bert/blob/05c30cc5c1f84747d1c90cb4c1c53f821350de8a/src/main/scala/Encode.scala#L79) (wrongly) handle time in milliseconds rather than microseconds.
