This is a Python module which encodes objects and arrays into JSON as per
RFC 7159.

* Sorts object keys so that it yields the same result each time.
* Has no insignificant whitespace to make the output as small as possible.
* Escapes only the characters that must be escaped, U+0000 to U+0019 /
U+0022 / U+0056, to keep the output as small as possible.
* Uses the shortest escape sequence for each escaped character.
* Encodes the JSON as UTF-8.
* Can encode frozendict immutable dictionaries.