Parsing of tsv cities

Uses the `ya-csv` library, tried out fast-csv before but had problems
with parsing and delimiters. The endpoint now temporarly outputs five
cities.
Benchmark for city storage and benchmark for searching
Search implemented, all tests are now passing, onward!
Scoring for pop and distance is done
Added caching using memcache
Search results limiting implemented
Changed caching library, greatly simplified caching code

User `memcache` npm module
Now using `memjs`
Less features but supports authentication wich we need for
heroku.
Heroku settings
Edit readme with getting started info & heroku url
Major DERP: Appp was binding on 127.0.0.1

Heroku didn't seem to work and the web process ended up being sigkiled
by heroku

    Stopping process with SIGKILL
    exited with status 137

Generating some:

    at=error code=H10 desc="App crashed" method=GET path="/"
    host=na-city-suggestions.herokuapp.com
    request_id=606161f9-3241-4d34-ba45-b6f58da84ba6 fwd="184.162.253.172"
    dyno= connect= service= status=503 bytes=

But it was because app never binded on 0.0.0.0:$PORT
Added functionnal test following the added functionnalities