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.

vendor/github.com/laramiel/BUILD

@@ -0,0 +1,7 @@
+load("@bazel_tools//tools/build_rules/go:def.bzl", "go_library")
+
+go_library(
+    name = "bare",
+    srcs = [ "bazel-example-golang-bare/bare.go" ],
+    visibility = ["//visibility:public"],
+)