Version bump to 0.4 release.
Version bump to 0.4 release.

Key changes:
- Python 3.x support;
- UBJSON Draft-9 support with Draft-8 at one time;
- Small perfomance boost;
- Break all things, that had directly relayed on decode/encode modules.

brainwater/simpleubjson,samipshah/simpleubjson,498888197/simpleubjson,kxepal/simpleubjson