Add Cloud TPU v1alpha1 API dependency

vendor/google.golang.org/api/tpu/v1alpha1/BUILD

@@ -0,0 +1,28 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["tpu-gen.go"],
+    importpath = "google.golang.org/api/tpu/v1alpha1",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//vendor/golang.org/x/net/context:go_default_library",
+        "//vendor/golang.org/x/net/context/ctxhttp:go_default_library",
+        "//vendor/google.golang.org/api/gensupport:go_default_library",
+        "//vendor/google.golang.org/api/googleapi:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)