[Fix bug 1093578] Add travis support.

I added that because it is required here [1] and here [2]. We could instead manually add a couple of ``COUNTRIES`` strings instead of requiring the whole ``.json`` file with the ``product_details``. 

[1] https://github.com/mozilla/remo/blob/15048e94f01044cb643e5c2e9ce4ff579fd357fb/remo/events/tests/__init__.py#L18
[2] https://github.com/mozilla/remo/blob/15048e94f01044cb643e5c2e9ce4ff579fd357fb/remo/profiles/tests/__init__.py#L10