chore(ci): remove node4 test target from travis-ci (#2054) r=vladikoff
chore(ci): remove node4 test target from travis-ci (#2054) r=vladikoff


eoger/fxa-auth-server,mozilla/fxa-auth-server,mozilla/fxa-auth-server,mozilla/fxa-auth-server,eoger/fxa-auth-server,eoger/fxa-auth-server,eoger/fxa-auth-server,mozilla/fxa-auth-server