ztk 2.4.0

• coveralls 0.8.23 >= 0

• pry 0.15.0 >= 0

• rake 13.2.1 >= 0

• redcarpet 3.6.0 >= 0

• rspec 3.13.0 >= 0

• simplecov-rcov 0.3.7 >= 0

• travis 1.14.0 >= 0

• typhoeus 0.6.9 ~> 0.6.7

• websocket-native 1.0.0 >= 0

• yard 0.9.37 >= 0

• yarjuf 2.0.0 >= 0