[test][bcp] Mark test_execute as flaky

This test tends to fail on macOS with Python3.7

It is however unclear why as the test passes most
of the time. Especially in the other CI environments.

beat/core/test/test_bcp.py

@@ -44,6 +44,8 @@ import zmq
 
 import simplejson as json
 
+from flaky import flaky
+
 from ..bcpapi import BCP
 from ..bcpapi.client import BeatComputationClient
 from ..bcpapi.execution import ExecutionProcess
@@ -311,6 +313,7 @@ class TestBCP(ExcecutionTestCase):
         self.assertEqual(messages[2][1], BCP.BCPP_JOB_CANCELLED)
         self.assertEqual(messages[2][2], job_id)
 
+    @flaky(max_runs=3)
     def test_execute(self):
         self.prepare_databases(CONFIGURATION1)
         job_id = b"1"