chore(package): update log4js to version 0.6.28
chore(package): update log4js to version 0.6.28

http://greenkeeper.io/
SamuelMarks/karma,karma-runner/karma,kahwee/karma,kahwee/karma,maksimr/karma,pedrotcaraujo/karma,wesleycho/karma,wesleycho/karma,panrafal/karma,david-garcia-nete/karma,marthinus-engelbrecht/karma,Dignifiedquire/karma,mprobst/karma,marthinus-engelbrecht/karma,buley/karma,shirish87/karma,mprobst/karma,Dignifiedquire/karma,karma-runner/karma,maksimr/karma,shirish87/karma,ernsheong/karma,johnjbarton/karma,pedrotcaraujo/karma,buley/karma,panrafal/karma,johnjbarton/karma,david-garcia-nete/karma,kahwee/karma,SamuelMarks/karma,johnjbarton/karma,maksimr/karma,Dignifiedquire/karma,pedrotcaraujo/karma,marthinus-engelbrecht/karma,ernsheong/karma,karma-runner/karma,david-garcia-nete/karma,ernsheong/karma,marthinus-engelbrecht/karma,kahwee/karma,wesleycho/karma,panrafal/karma,pedrotcaraujo/karma,SamuelMarks/karma,karma-runner/karma,mprobst/karma,Dignifiedquire/karma,buley/karma,johnjbarton/karma,shirish87/karma,buley/karma,wesleycho/karma