travis: update ruby 2.4.1, 2.3.4, 2.2.6
travis: update ruby 2.4.1, 2.3.4, 2.2.6

bm-sms/daimon-skycrawlers,bm-sms/daimon_skycrawlers,bm-sms/daimon_skycrawlers,bm-sms/daimon-skycrawlers,bm-sms/daimon_skycrawlers