Revert "Remove double consonants that do not take a sokuon, according to https://en.wikipedia.org/wiki/Sokuon"
Revert "Remove double consonants that do not take a sokuon, according to https://en.wikipedia.org/wiki/Sokuon"

This reverts commit 1a0c293725a6411126500624904d2cc6bef9ddf0.

Revert commit 1a0c293725a6411126500624904d2cc6bef9ddf0 that removed the
superfluous double consonants tests, because they seem to be intended

WaniKani/WanaKana,WaniKani/WanaKana