fix validation script to sort alphabetically

[tasawernawaz]

Fixes #82

FYI @benbarth

[benbarth]

Thanks @tasawernawaz! I think we should switch it to "key=str.casefold".

str.casefold()
Return a casefolded copy of the string. Casefolded strings may be used for caseless matching.

Casefolding is similar to lowercasing but more aggressive because it is intended to remove all case distinctions in a string. For example, the German lowercase letter 'ß' is equivalent to "ss". Since it is already lowercase, lower() would do nothing to 'ß'; casefold() converts it to "ss".

The casefolding algorithm is described in section 3.13 of the Unicode Standard.

New in version 3.3.