error bubbling w/o message

[travi]

I havent completely tracked down the issue, but in trying to determine the cause of semantic-release/semantic-release#337, I'm fairly certain that an error from this module is bubbling through condition-travis to the callback for plugins.verifyConditions, resulting in undefined when attempting to log err.message.

Without that output, I'm not seeing anything obvious in the code, but I'm hoping the combination of these two issues might provide enough that it triggers a thought for you. I'm happy to provide any additional information that could be helpful.

[travi]

It may be important to note that the failing jobs are running on Travis Pro. I have several projects running successfully on public Travis.

[travi]

It looks like there are a number of possible errors from node-travis-ci that are not returned as Error objects, but instead as strings. Because of this any of them would not have then message property, but instead would result in undefined when accessing message.

It would be nice if this package would normalize the errors so that consumers, like the callback for plugins.verifyConditions could confidently access the message of the error.