How to resolve dependency from vendor?

[rhzs]

I have an issue with dependency from dependent library. Let's say I need to perform testing with go test. As follow:

go on  master via 🐹 v1.1
➜ go test github.com/incubus8/go/pkg/gin
vendor/github.com/gin-gonic/gin/binding/default_validator.go:11:2: cannot find package "gopkg.in/go-playground/validator.v8" in any of:
	/Users/angel/go/src/github.com/incubus8/go/vendor/github.com/gin-gonic/gin/vendor/gopkg.in/go-playground/validator.v8 (vendor tree)
	/Users/angel/go/src/github.com/incubus8/go/vendor/gopkg.in/go-playground/validator.v8
	/usr/local/opt/go/libexec/src/gopkg.in/go-playground/validator.v8 (from $GOROOT)
	/Users/angel/go/src/gopkg.in/go-playground/validator.v8 (from $GOPATH)
vendor/github.com/gin-gonic/gin/render/yaml.go:10:2: cannot find package "gopkg.in/yaml.v2" in any of:
	/Users/angel/go/src/github.com/incubus8/go/vendor/github.com/gin-gonic/gin/vendor/gopkg.in/yaml.v2 (vendor tree)
	/Users/angel/go/src/github.com/incubus8/go/vendor/gopkg.in/yaml.v2
	/usr/local/opt/go/libexec/src/gopkg.in/yaml.v2 (from $GOROOT)
	/Users/angel/go/src/gopkg.in/yaml.v2 (from $GOPATH)
go on  master via 🐹 v1.1
➜ manul -I gopkg.in/yaml.v2
2018-04-14 17:05:45 [FATAL]: unknown dependency: gopkg.in/yaml.v2

go on  master via 🐹 v1.1 took 5s
➜ manul -I gopkg.in/go-playground/validator.v8
2018-04-14 17:05:52 [FATAL]: unknown dependency: gopkg.in/go-playground/validator.v8

go on  master via 🐹 v1.1 took 4s
➜ go test github.com/incubus8/go/pkg/gin
vendor/github.com/gin-gonic/gin/binding/default_validator.go:11:2: cannot find package "gopkg.in/go-playground/validator.v8" in any of:
	/Users/angel/go/src/github.com/incubus8/go/vendor/github.com/gin-gonic/gin/vendor/gopkg.in/go-playground/validator.v8 (vendor tree)
	/Users/angel/go/src/github.com/incubus8/go/vendor/gopkg.in/go-playground/validator.v8
	/usr/local/opt/go/libexec/src/gopkg.in/go-playground/validator.v8 (from $GOROOT)
	/Users/angel/go/src/gopkg.in/go-playground/validator.v8 (from $GOPATH)
vendor/github.com/gin-gonic/gin/render/yaml.go:10:2: cannot find package "gopkg.in/yaml.v2" in any of:
	/Users/angel/go/src/github.com/incubus8/go/vendor/github.com/gin-gonic/gin/vendor/gopkg.in/yaml.v2 (vendor tree)
	/Users/angel/go/src/github.com/incubus8/go/vendor/gopkg.in/yaml.v2
	/usr/local/opt/go/libexec/src/gopkg.in/yaml.v2 (from $GOROOT)
	/Users/angel/go/src/gopkg.in/yaml.v2 (from $GOPATH)

How can I resolve that using Manul? Need help.