bots: Move contrib_bots to api/bots*.

This will make it convenient to include these bots in Zulip API
releases on pypi.

Fix #5009.

bots_api/test-bots

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+from __future__ import absolute_import
+from __future__ import print_function
+
+import argparse
+import os
+import sys
+import unittest
+from unittest import TestCase
+
+def dir_join(dir1, dir2):
+    # type: (str, str) -> str
+    return os.path.abspath(os.path.join(dir1, dir2))
+
+
+if __name__ == '__main__':
+    description = 'Script to run test_<bot>.py files in bots/<bot> directories'
+    parser = argparse.ArgumentParser(description=description)
+    parser.add_argument('--bot',
+                        nargs=1,
+                        type=str,
+                        action='store',
+                        help='test specified single bot')
+    args = parser.parse_args()
+
+    bots_dir = os.path.dirname(os.path.abspath(__file__))
+    root_dir = dir_join(bots_dir, '..')
+    bots_test_dir = dir_join(bots_dir, '../bots')
+
+    sys.path.insert(0, root_dir)
+    sys.path.insert(0, bots_test_dir)
+
+    # mypy doesn't recognize the TestLoader attribute, even though the code
+    # is executable
+    loader = unittest.TestLoader() # type: ignore
+    if args.bot is not None:
+        bots_test_dir = dir_join(bots_test_dir, args.bot[0])
+    suite = loader.discover(start_dir=bots_test_dir, top_level_dir=root_dir)
+    runner = unittest.TextTestRunner(verbosity=2)
+    # same issue as for TestLoader
+    result = runner.run(suite) # type: ignore
+    if result.errors or result.failures:
+        raise Exception('Test failed!')