chore(travis): Test on node@4
chore(travis): Test on node@4

astorije/karma,kahwee/karma,wesleycho/karma,simudream/karma,marthinus-engelbrecht/karma,marthinus-engelbrecht/karma,karma-runner/karma,mprobst/karma,pmq20/karma,SamuelMarks/karma,maksimr/karma,ernsheong/karma,maksimr/karma,johnjbarton/karma,pedrotcaraujo/karma,codedogfish/karma,maksimr/karma,harme199497/karma,chrisirhc/karma,shirish87/karma,karma-runner/karma,buley/karma,simudream/karma,shirish87/karma,harme199497/karma,Dignifiedquire/karma,skycocker/karma,xiaoking/karma,david-garcia-nete/karma,pedrotcaraujo/karma,SamuelMarks/karma,ernsheong/karma,Dignifiedquire/karma,marthinus-engelbrecht/karma,Dignifiedquire/karma,johnjbarton/karma,codedogfish/karma,pedrotcaraujo/karma,kahwee/karma,wesleycho/karma,pmq20/karma,astorije/karma,pedrotcaraujo/karma,astorije/karma,harme199497/karma,oyiptong/karma,marthinus-engelbrecht/karma,xiaoking/karma,chrisirhc/karma,ernsheong/karma,karma-runner/karma,xiaoking/karma,pmq20/karma,wesleycho/karma,david-garcia-nete/karma,simudream/karma,skycocker/karma,mprobst/karma,buley/karma,wesleycho/karma,chrisirhc/karma,shirish87/karma,panrafal/karma,skycocker/karma,mprobst/karma,oyiptong/karma,chrisirhc/karma,astorije/karma,codedogfish/karma,codedogfish/karma,david-garcia-nete/karma,skycocker/karma,Dignifiedquire/karma,simudream/karma,karma-runner/karma,panrafal/karma,pmq20/karma,kahwee/karma,harme199497/karma,oyiptong/karma,buley/karma,johnjbarton/karma,johnjbarton/karma,SamuelMarks/karma,xiaoking/karma,kahwee/karma,buley/karma,oyiptong/karma,panrafal/karma