Python exceptions raised during integration test runs should be handled gracefully

When an error is encountered while running the Boulder Integration Test suite not all exceptions are being caught during the initialization of the chisel client. This results in a stack trace being during the Integration Test. Ideally, all python exceptions should be caught and handled gracefully, instead of outputting a stack trace during Integration Tests

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Traceback (most recent call last):
  File "test/integration-test.py", line 388, in <module>
    main()
  File "test/integration-test.py", line 251, in main
    v1_integration.caa_client = caa_client = chisel.make_client()
  File "/go/src/github.com/letsencrypt/boulder/test/chisel.py", line 53, in make_client
    account = client.register(messages.NewRegistration.from_data(email=email))
  File "/usr/local/lib/python3.5/dist-packages/acme/client.py", line 279, in register
    response = self._post(self.directory[new_reg], new_reg)
  File "/usr/local/lib/python3.5/dist-packages/acme/client.py", line 97, in _post
    return self.net.post(*args, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/acme/client.py", line 1201, in post
    return self._post_once(*args, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/acme/client.py", line 1214, in _post_once
    response = self._check_response(response, content_type=content_type)
  File "/usr/local/lib/python3.5/dist-packages/acme/client.py", line 1072, in _check_response
    raise messages.Error.from_json(jobj)
acme.messages.Error: urn:acme:error:unauthorized :: The client lacks sufficient authorization :: Account creation on ACMEv1 is disabled. Please upgrade your ACME client to a version that supports ACMEv2 / RFC 8555. See https://community.letsencrypt.org/t/end-of-life-plan-for-acmev1/88430 for details.

Start in test/integration-test.py at main(), where v1_integration.caa_client is initialized through chisel.make_client(), then read test/chisel.py around make_client(). Reproduce the integration-test failure and identify how initialization errors are currently surfaced. Done means Python exceptions during this setup are handled gracefully without printing a stack trace.