update maven requirement in docs.
update maven requirement in docs.

AriSuutariST/waffle,victorbriz/waffle,dblock/waffle,hazendaz/waffle,dblock/waffle,boyley/waffle,Waffle/waffle,vimil/waffle,Waffle/waffle,Waffle/waffle,AriSuutariST/waffle,dblock/waffle,vimil/waffle,boyley/waffle,victorbriz/waffle,hazendaz/waffle,dblock/waffle,vimil/waffle,victorbriz/waffle,boyley/waffle,hazendaz/waffle,vimil/waffle,AriSuutariST/waffle,AriSuutariST/waffle