Add IOC country codes

[Azrael3000]

Add International Olympic Committee country codes

Data basis: https://en.wikipedia.org/wiki/List_of_IOC_country_codes

Would be great to have this in the country_converter tool, which is fantastic by the way :)

Cheers,
Arno

[coveralls]

coverage: 97.03%. remained the same
when pulling e97fc81 on Azrael3000:master
into f912881 on IndEcol:master.

[konstantinstadler]

Thanks a lot for that, should be in version 1.2 in the next days!