Vendor godep v79 and use it

vendor/github.com/tools/godep/path.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+var cmdPath = &Command{
+	Name:  "path",
+	Short: "print GOPATH for dependency code",
+	Long: `
+Command path prints a path for use in env var GOPATH
+that makes available the specified version of each dependency.
+
+The printed path does not include any GOPATH value from
+the environment.
+
+For more about how GOPATH works, see 'go help gopath'.
+`,
+	Run:          runPath,
+	OnlyInGOPATH: true,
+}
+
+// Print the gopath that points to
+// the included dependency code.
+func runPath(cmd *Command, args []string) {
+	if len(args) != 0 {
+		cmd.UsageExit()
+	}
+	if VendorExperiment {
+		fmt.Fprintln(os.Stderr, "Error: GO15VENDOREXPERIMENT is enabled and the vendor/ directory is not a valid Go workspace.")
+		os.Exit(1)
+	}
+	gopath := prepareGopath()
+	fmt.Println(gopath)
+}