vpython: Add VirtualEnv creation package.

vpython/venv/test_data/setup_check.py

+# Copyright 2017 The LUCI Authors. All rights reserved.
+# Use of this source code is governed under the Apache License, Version 2.0
+# that can be found in the LICENSE file.
+
+import argparse
+import json
+import sys
+
+# Also, import our two VirtualEnv packages.
+import pants
+import shirt
+
+
+def main(args):
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--json-output',
+      help='JSON output path.')
+  opts = parser.parse_args(args)
+
+  manifest = {
+      'interpreter': sys.executable,
+      'pants': pants.__file__,
+      'shirt': shirt.__file__,
+  }
+
+  if opts.json_output:
+    with open(opts.json_output, 'w') as fd:
+      json.dump(manifest, fd)
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))