update code of conduct to reflect upstream content
Merge branch 'update_c_o_c' of github.com:RailsBridge-CapeTown/rails-bridge-capetown.github.com into update_c_o_c
Tighten up CoC, AHP: remove repeats, clarify.
Merge pull request #13 from RailsBridge-CapeTown/update_c_o_c

Update code of conduct