from tictactoe to gobblet

remark

• original tictactoe repo is here

what I have done

• using Registry in Elixir 1.4 instead of gproc.
• error message from original repo: link.
• bug from original repo: when one game is finished, no player clicks the new game button, then a player logs out and another player joins the previous game, the game is stuck.

what I aim at: repo

• replace js by elm
• extend tictictoe to gobblet