Rename `lat` and `lon` fields to `latitude` and `longitude`
For easier compatibility with Geocoder gem
Geocode addresses automatically using Google geocoding API
* it geocodes location only when latitude and longitude coordinates aren't provided
* add a FakeGeocoder object for clear tests. We could use Geocoder built-in solution
but it makes the tests obscures and harder to understand as the expected coordinates
of an address, are set somewhere else, far from the test itself.

https://github.com/alexreisner/geocoder#testing-apps-that-use-geocoder
https://trello.com/c/wbTFtHx9
Add 'FR' as the default `country_code` for places.
Avoid geocoding if the address hasn't changed
https://trello.com/c/L4gljgNs
Rename `address` field to `street`, which is more precise
https://trello.com/c/GNlKItUY
Revert 'Unignore .env' and replace it by `.sample.env`
This reverts commit 8bbf4c2a47f330b083aa1c7e17ff17d52335a7f2.
https://trello.com/c/lpy5DU0t
Fix Travis conf
- make sure `.env` file is available
- remove IRC notifications
- remove unnecessary config options
https://trello.com/c/5L59pIZJ
Add search panel to Places#index
Let the user close a Place when viewing it (and going back to the search)
Rename code into id, as Emberjs need an id field
Display kinds checkboxes
Use a dedicated ObjectController for handling kinds
Persist selected kinds
Make the filters system work
Minor css fix for filters checkboxes
Use an ObjectController to display a Place instead of a standard Controller