Now python3.6 can be installed from apt and it will be installed with
all submodules.

If we're compiling Python from source, during compilation we get:

```
The necessary bits to build these optional modules were not found:
_bz2                  _dbm                  _gdbm
_lzma                 _sqlite3              _tkinter
readline
```

which then results in

```
==================== Test output for //bazel_pip/tensorflow/contrib/summary:summary_ops_test:
Running test /tmpfs/src/github/tensorflow/bazel-ci_build-cache/.cache/bazel/_bazel_kbuilder/eab0d61a99b6696edb3d2aff87b585e8/execroot/org_tensorflow/bazel-out/k8-opt/bin/bazel_pip/tensorflow/contrib/summary/summary_ops_test.runfiles/org_tensorflow/bazel_pip/tensorflow/contrib/summary/summary_ops_test  on GPU 0
Traceback (most recent call last):
  File "/tmpfs/src/github/tensorflow/bazel-ci_build-cache/.cache/bazel/_bazel_kbuilder/eab0d61a99b6696edb3d2aff87b585e8/execroot/org_tensorflow/bazel-out/k8-opt/bin/bazel_pip/tensorflow/contrib/summary/summary_ops_test.runfiles/org_tensorflow/bazel_pip/tensorflow/contrib/summary/summary_ops_test.py", line 23, in <module>
    import sqlite3
  File "/usr/local/lib/python3.6/sqlite3/__init__.py", line 23, in <module>
    from sqlite3.dbapi2 import *
  File "/usr/local/lib/python3.6/sqlite3/dbapi2.py", line 27, in <module>
    from _sqlite3 import *
ModuleNotFoundError: No module named '_sqlite3'
================================================================================
```

and similar failures which then block releasing patch version.

PiperOrigin-RevId: 249272809

PiperOrigin-RevId: 248366536

PiperOrigin-RevId: 248373911

Update header on release notes

Update version to 1.12.2

Fix windows build for CPU too

Add --incompatible_disable_cc_toolchain_label_from_crosstool_proto

Add --incompatible_remove_native_http_archive=false to windows bazel calls

Remove the debug changes

Display bazel log file on trapped cleanup.

Temporarily add debug options on bazel build

Disable one more flaky test

Disable one more macos test for python35

Disable 3 tests which fail on tf 1.12.1.

Release notes for patch release 1.12.1

[cherrypick] Move bazel.rc to workspace root to support bazel-0.18.0

Bazel 0.18.0 will contain a change for which rc files it accepts.
https://github.com/bazelbuild/bazel/commit/ec83598cb6ee4136166bb562a24dc5dfa58921db
https://github.com/bazelbuild/bazel/issues/4502

Old bazel used to read %workspace%/tools/bazel.rc. New bazel will not
read that and instead will only read %workspace%/.bazelrc.
Signed-off-by: NJason Zaman <jason@perfinion.com>

--define=grpc_no_ares=true to make MacOS builds work

Disable keras:applications_test (128912960)