iaas/ec2: use custom http.Client for aws connections
iaas/ec2: use custom http.Client for aws connections

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