Removing tty from exec to work around "command exited with code 129"

This is based on
docker/compose#3379 (comment)
and may address
https://git.corp.adobe.com/dms-release-engineering/buildrunner/issues/78.

buildrunner/docker/runner.py

@@ -220,7 +220,7 @@ def run(self, cmd, console=None, stream=True):
         create_res = self.docker_client.exec_create(
             self.container['Id'],
             [self.shell, '-c', cmd],
-            tty=True,
+            tty=False,
         )
         output_buffer = self.docker_client.exec_start(
             create_res,