Api fails when not terminus is provided in the result

[stanislasgodel]

There are cases when the sncf API doesn't return a terminus for train' it's documented in the api as a case occurring if the terminus is not known in the referencial of stations of transilien.
For instance, it happens regularly when trying to get the results for Paris Saint Lazare.
In that case, there's an un aught exception raised in format module . extractNode tries to call unshift on a undefined value.

[j5lien]

Thanks for the info, I'm not sure to have the time for a fix quickly but feel free to make a PR.