Fix KeyError on spec failure

[johnsca]

There seems to be a case where a test result can not get a name assigned.

ERROR:runner:Timeout exceeded. Failed to destroy all applications  in 60 seconds.
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/bundletester/runner.py", line 180, in _run_test
    self.builder.reset()
  File "/usr/local/lib/python2.7/dist-packages/bundletester/builder.py", line 140, in reset
    ' in %s seconds.' % timeout)
RuntimeError: Timeout exceeded. Failed to destroy all applications  in 60 seconds.
cs:~juju-solutions/cwr
Traceback (most recent call last):
  File "/usr/local/bin/bundletester", line 11, in <module>
    sys.exit(entrypoint())
  File "/usr/local/lib/python2.7/dist-packages/bundletester/tester.py", line 157, in entrypoint
    status = main()
  File "/usr/local/lib/python2.7/dist-packages/bundletester/tester.py", line 146, in main
    [report.emit(result) for result in run()]
  File "/usr/local/lib/python2.7/dist-packages/bundletester/reporter.py", line 147, in emit
    cmd = message.test
  File "/usr/local/lib/python2.7/dist-packages/bundletester/reporter.py", line 16, in __getattr__
    return self[k]
KeyError: 'test'
Build step 'Execute shell' marked build as failure