Attempt to fix Windows Bazel build.

Excluded dependency on contrib/bigtable from Windows build.
There are several Bazel build errors when trying to build it.

Author: Michael Case

tensorflow/contrib/BUILD

@@ -25,7 +25,6 @@ py_library(
         "//tensorflow/contrib/all_reduce",
         "//tensorflow/contrib/batching:batch_py",
         "//tensorflow/contrib/bayesflow:bayesflow_py",
-        "//tensorflow/contrib/bigtable",
         "//tensorflow/contrib/boosted_trees:init_py",
         "//tensorflow/contrib/checkpoint/python:checkpoint",
         "//tensorflow/contrib/cloud:cloud_py",
@@ -127,6 +126,7 @@ py_library(
     }) + if_not_windows_cuda([
         "//tensorflow/contrib/fused_conv:fused_conv_py",  # unresolved symbols, need to export more symbols
     ]) + if_not_windows([
+        "//tensorflow/contrib/bigtable",
         "//tensorflow/contrib/ffmpeg:ffmpeg_ops_py",
         "//tensorflow/contrib/lite/python:lite",  # unix dependency, need to fix code
     ]),