Can't run vmtests directly per documentation on trunk

[Chad Smith]

Reading through docs at
http://curtin.readthedocs.io/en/latest/topics/integration-testing.html#setup

I've tried following the vmtest setup on a fresh yaketty system

make vmtest-deps
make vmtest

At first it fell over due to a missing dependency on "route" but now unit tests run and error for all tests with the following types of failure mode:

======================================================================
ERROR: test suite for <class 'vmtests.test_vmtests.PsuedoTestMixedPassAndFail'>
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/nose/suite.py", line 210, in run
    self.setUp()
  File "/usr/lib/python3/dist-packages/nose/suite.py", line 293, in setUp
    self.setupContext(ancestor)
  File "/usr/lib/python3/dist-packages/nose/suite.py", line 316, in setupContext
    try_run(context, names)
  File "/usr/lib/python3/dist-packages/nose/util.py", line 471, in try_run
    return func()
  File "/home/csmith/src/curtin/curtin/tests/vmtests/__init__.py", line 823, in setUpClass
    cls.reporting_log], capture=True)
  File "/home/csmith/src/curtin/curtin/curtin/util.py", line 194, in subp
    return _subp(*args, **kwargs)
  File "/home/csmith/src/curtin/curtin/curtin/util.py", line 127, in _subp
    cmd=args)
curtin.util.ProcessExecutionError: Unexpected error while running command.
Command: ['tools/curtin-log-print', '--dumpfiles', '/tmp/vmtest-2017-04-20T103246.196813/PsuedoTestMixedPassAndFail/logs', '/tmp/vmtest-2017-04-20T103246.196813/PsuedoTestMixedPassAndFail/logs/webhooks-events.json']
Exit code: 2
Reason: -
Stdout: ''
Stderr: usage: curtin-print-log [-h] [--dumpfiles DUMP_FILES] [--save-processing-data]
                                [--format PRINT_FORMAT]
                                [infile]
        curtin-print-log: error: argument infile: can't open '/tmp/vmtest-2017-04-20T103246.196813/PsuedoTestMixedPassAndFail/logs/webhooks-events.json': [Errno 2] No such file or directory: '/tmp/vmtest-2017-04-20T103246.196813/PsuedoTestMixedPassAndFail/logs/webhooks-events.json'

I'm thinking this could be related to the recent changes that landed in rev 488. Or maybe a missing dependency in my test environment.