Add the vendor/ path, and add git submodules to the appropriate

subdirectory paths under vendor/

The intent is to make use of the golang 1.6 VENDOR extension
to build. As seen, the bare example does not correctly build
using bazel in this mode.

with_vendor/remote.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/laramiel/bazel-example-golang-remote/remote"
+)
+
+func main() {
+	fmt.Println("Hello", remote.World())
+}