Fixed typo in tribute to Ara Howard.
Fixed typo in tribute to Ara Howard.

coreyhaines/ruby_koans,kaichanvong/Ruby-Koans,seankibler/ruby_koans,c-wade/Ruby-Koans,Jayphen/Ruby-Kegels,filipzalewski/ruby_koans,rizwanreza/ruby_koans,ozzloy/ruby_koans,dsryan/ruby-koans