Fixing invalid test for 10 digits with letters
Fixing invalid test for 10 digits with letters

`test_invalid_when_10_digits_with_extra_letters` is broken since it should test for 10 digits, but instead tests for 9.

wobh/xruby,NeimadTL/ruby,exercism/xruby,jdsayle/xruby,alexbrinkman/xruby,mamenama/xruby,wobh/xruby,NeimadTL/ruby,tommyschaefer/xruby,mamenama/xruby,Insti/exercism-ruby,rashmiagar/exercism,darrencauthon/xruby,remcopeereboom/xruby,samilokan/xruby,alexbrinkman/xruby,gchan/xruby,exercism/xruby,remcopeereboom/xruby,dalexj/xruby,NobbZ/xruby,Calvyn82/xruby,Insti/xruby,darrencauthon/xruby,kickinbahk/xruby,jdsayle/xruby,Calvyn82/word_count,NobbZ/xruby,samilokan/xruby,NeimadTL/ruby,kickinbahk/xruby,rashmiagar/exercism,dalexj/xruby,tommyschaefer/xruby,kotp/xruby,Calvyn82/word_count,Insti/exercism-ruby,gchan/xruby,Calvyn82/xruby,Insti/exercism-ruby,JordyOne/exercism-practice,Insti/xruby,kotp/xruby