Build trigger to test TensorFlow bridge against PRs (#2748)

* First rev of NGTF build from nGraph

* Copyright year update

* WIP

* Update test_ngtf_build.py

Updated with the latest repo URL

.ci/buildkite/test_ngtf_build.py

+#!/usr/bin/env python3
+# ==============================================================================
+#  Copyright 2019 Intel Corporation
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+# ==============================================================================
+import argparse
+import errno
+import os
+from subprocess import check_output, call
+import sys
+import shutil
+import glob
+import platform
+import json
+import shlex
+
+def command_executor(cmd, verbose=False, msg=None, stdout=None):
+    '''
+    Executes the command.
+    Example: 
+      - command_executor('ls -lrt')
+      - command_executor(['ls', '-lrt'])
+    '''
+    if type(cmd) == type([]):  #if its a list, convert to string
+        cmd = ' '.join(cmd)
+    if verbose:
+        tag = 'Running COMMAND: ' if msg is None else msg
+        print(tag + cmd)
+    if (call(shlex.split(cmd), stdout=stdout) != 0):
+        raise Exception("Error running command: " + cmd)
+
+def download(target_name, repo, version):
+
+    # First download to a temp folder
+    call(["git", "clone", repo, target_name])
+
+    # Next goto this folder nd determone the name of the root folder
+    pwd = os.getcwd()
+
+    # Go to the tree
+    os.chdir(target_name)
+
+    # checkout the specified branch
+    command_executor(["git", "fetch"], verbose=True)
+    command_executor(["git", "checkout", version], verbose=True)
+
+    os.chdir(pwd)
+
+# Get me the current sha for this commit
+current_sha = check_output(['git', 'rev-parse', 'HEAD']).strip().decode("utf-8")
+print("nGraph SHA: ", current_sha)
+
+# Download ngraph-bridge 
+download('ngraph-bridge', 'https://github.com/tensorflow/ngraph-bridge.git', 'master')
+
+# Run ngraph-bridge-build
+pwd = os.getcwd()
+os.chdir('ngraph-bridge')
+command_executor(['./build_ngtf.py', '--ngraph_version', current_sha])
+
+# Now run the tests
+os.environ['PYTHONPATH'] = os.getcwd() 
+command_executor([
+    'python3',
+    'test/ci/buildkite/test_runner.py',
+    '--artifacts',
+    'build_cmake/artifacts',
+    '--test_cpp'
+])
+
+os.chdir(pwd)