Updated ISO 4217 currency database

0.11.3

Updated ISO 4217 currency database.

Updated documentation.

0.11.2

Updated CHANGES.

Complete redesign with simplified meta classes.

API not compatible to previous version!
Required Python version set to 3.7.
Updated required version of 'decimalfp' to 0.11.4.
Added 'pytest' as required for tests.
Ported tests to 'pytest'.
Added module defining SI prefixes.
Reformatted code and fixed names according to PEP 8.
Added and revised test cases and type hints.

Release 0.10.1

Updated ISO 4217 currency database.

Release 0.10.0

Dropped compatibility with Python 2.x.
Set required Python version to 3.6.
Updated required version of 'decimalfp' to 0.11.1.
Changed project layout.