Update go mod (#51)

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/docker/go-units v0.3.3 // indirect
 	github.com/fatih/color v1.7.0
 	github.com/goware/urlx v0.0.0-20171129014730-06d8eeb3ce17
+	github.com/hashicorp/go-retryablehttp v0.5.1-0.20181126172515-dfbae6744eb4
 	github.com/mattn/go-colorable v0.0.9 // indirect
 	github.com/mattn/go-isatty v0.0.4 // indirect
 	github.com/pkg/errors v0.8.0

go.sum

@@ -20,6 +20,12 @@ github.com/fatih/color v1.7.0 h1:DkWD4oS2D8LGGgTQ6IvwJJXSL5Vp2ffcQg58nFV38Ys=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/goware/urlx v0.0.0-20171129014730-06d8eeb3ce17 h1:6Gt5nbCTJ4YjqdJstMOLpyquzZMYpd01YZ/Kvaw6iPs=
 github.com/goware/urlx v0.0.0-20171129014730-06d8eeb3ce17/go.mod h1:Zn362WbIrTvMfW1tj4MxrEct8vJtNlnljZPnRssPfDU=
+github.com/hashicorp/go-cleanhttp v0.5.0 h1:wvCrVc9TjDls6+YGAF2hAifE1E5U1+b4tH6KdvN3Gig=
+github.com/hashicorp/go-cleanhttp v0.5.0/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
+github.com/hashicorp/go-retryablehttp v0.5.0 h1:aVN0FYnPwAgZI/hVzqwfMiM86ttcHTlQKbBVeVmXPIs=
+github.com/hashicorp/go-retryablehttp v0.5.0/go.mod h1:9B5zBasrRhHXnJnui7y6sL7es7NDiJgTc6Er0maI1Xs=
+github.com/hashicorp/go-retryablehttp v0.5.1-0.20181126172515-dfbae6744eb4 h1:UqfwdlQeQqgQ3oO4qziqqTOwg4EwcZjX/xv9adH8ftI=
+github.com/hashicorp/go-retryablehttp v0.5.1-0.20181126172515-dfbae6744eb4/go.mod h1:9B5zBasrRhHXnJnui7y6sL7es7NDiJgTc6Er0maI1Xs=
 github.com/mattn/go-colorable v0.0.9 h1:UVL0vNpWh04HeJXV0KLcaT7r06gOH2l4OW6ddYRUIY4=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.4 h1:bnP0vzxcAdeI1zdubAl5PjU6zsERjGZb7raWodagDYs=