travis: update go to 1.7.5
travis: update go to 1.7.5

guilhermebr/tsuru,tsuru/tsuru,ggarnier/tsuru,ggarnier/tsuru,tsuru/tsuru,cezarsa/tsuru,ArxdSilva/tsuru,cezarsa/tsuru,ArxdSilva/tsuru,guilhermebr/tsuru,ggarnier/tsuru,ggarnier/tsuru,cezarsa/tsuru,guilhermebr/tsuru,ArxdSilva/tsuru,ArxdSilva/tsuru,guilhermebr/tsuru,tsuru/tsuru,tsuru/tsuru,cezarsa/tsuru