only consider full import path as subpackages (#75)

gbvendor/manifest.go

diff --git a/gbvendor/manifest.go b/gbvendor/manifest.go
index d23b84e..54f304a 100644
--- a/gbvendor/manifest.go
+++ b/gbvendor/manifest.go
@@ -78,7 +78,7 @@
 // of the given import path.
 func (m *Manifest) GetSubpackages(path string) (deps []Dependency) {
 	for _, d := range m.Dependencies {
-		if path != d.Importpath && strings.HasPrefix(d.Importpath, path) {
+		if path != d.Importpath && strings.HasPrefix(d.Importpath, path+"/") {
 			deps = append(deps, d)
 		}
 	}