unit tests dependant on default pelias.json values

[missinglink]

I noticed today that when I have my own local ~/pelias.json file with values in import.whosonfirst then the tests fail.
Moving or deleting ~/pelias.json make the tests pass again.

I didn't dig into it further but I'm guessing that having countryCode: US set is what's causing the issue..

    "whosonfirst": {
      "datapath": "/data/wof/sqlite",
      "sqlite": true,
      "importPostalcodes":false,
      "countryCode": "US",
      "importPlace": ["85633793"]
    }

see: #520

[orangejulius]

Ah yeah, I might have seen this at some point too. If not in this repo, I'm pretty sure it's possible in others.

I think the easiest way around this sort of problem is to always use an empty pelias.json when running the tests, like we did in pelias/api#1431. It's not much work to set up, and it doesn't require going through all the unit tests to find which ones might possibly behave differently with non-standard pelias.json settings.