As with all Wikimedia projects, editors must take particular care when adding information about living persons to any Wikivoyage page.
Fortunately, though, this issue does not come up often on Wikivoyage, as we are in the business of writing about places, not people!
The two relatively rare situations where you are likely to run across information about living persons are as follows:
It would be hard to write a background section on Myanmar without mentioning Aung San Suu Kyi. The principal guideline for handling information about living persons in understand sections is covered by Wikivoyage:Be fair#Political disputes: stick to the bare minimum of facts necessary, presented as neutrally as possible, while keeping a firm focus on the traveller's interests.
Additionally, you should add references to a section on the article's talk page to source the information given in the article proper. Such references should be placed on the talk page—not on the article itself—under a section with a title matching the living person's name. Since you travel writers probably aren't too excited about tracking down references, just copy some from Wikipedia!
Sometimes travelers find it useful to share information about individuals they have come across in their travels, either because they were helpful or harmful. Thus someone might write that the Concierge at Hotel X in Paris is too busy drug dealing on the side to help hotel guests, or that Giorgi in Kazbegi is a loudmouth drunk, but will set you up with a homestay, and his wife will make you incredible khinkali. This type of information is trickier, since it is first hand original research—which we love!—but the first example could potentially land Wikivoyage's web hosts in a libel suit.
In these types of situations, follow Wikivoyage:Avoid negative reviews strictly. With regards to living persons, if you don't have anything nice to say, don't say anything at all.
In only the rarest of cases—if the establishment in question is too prominent and the case too egregious for us to drop coverage—we should include a negative review, and even then only if we have have iron-clad references, which must be added to the talk page.