TestOFECommandPlugin sometimes randomly fails

[richardjgowers]

This test occasionally fails, it is almost certainly a false positive as the rest of the CLI has worked.

============================================================================================================= FAILURES =============================================================================================================
______________________________________________________________________________________________ TestOFECommandPlugin.test_plugin_setup ______________________________________________________________________________________________

self = <openfecli.tests.test_plugins.TestOFECommandPlugin object at 0x>

    def test_plugin_setup(self):
>       assert self.plugin.command is fake
E       AttributeError: 'TestOFECommandPlugin' object has no attribute 'plugin'

[mikemhenry]

related #816

[mikemhenry]

also maybe related #610