[beam_PostCommit_Py_ValCont] build failed

See https://builds.apache.org/job/beam_PostCommit_Py_ValCont/5706/

Error:

 
16:12:13 The push refers to repository [us.gcr.io/apache-beam-testing/jenkins/python2.7_sdk]16:12:13 An image does not exist locally with the tag: us.gcr.io/apache-beam-testing/jenkins/python2.7_sdk*16:12:14* Build step 'Execute shell' marked build as failure*16:12:15* Sending e-mails to: builds@beam.apache.org*16:12:15* Recording test results*16:12:16* ERROR: Step 'Publish JUnit test result report' failed: No test report files were found. Configuration error?16:12:18 No emails were triggered.16:12:18 Finished: FAILURE