[Geocodable] Add a function to compute distances in meters.

The current `DISTANCE` function computes distances in miles using the
`<@>` postgresql operator.

This commit adds a function `DISTANCE_IN_METERS` that uses the
`earth_distance` and `ll_to_earth` functions to compute distances in
meters.

It also adds a new method `GeocodableRepository::findByDistanceInMeters()`.
Replaced the DISTANCE function with the new DISTANCE_IN_METERS one.

Instead of keeping BC, we simply fix the broken function.
Merge pull request #98 from kimlai/miles_kms

[Geocodable] Add a function to compute distances in meters.
Add doctrine default hints method mock
Merge pull request #126 from KnpLabs/fix/tests

Tests should be green.
remove composer.lock from version control

This file should not be under version control because this is a library,
which means you are not going to deploy it by itself.
install phpunit the bin folder

It is easier to access it that way.
Show how to easily run the test suite
Merge pull request #131 from greg0ire/ease_contributions

Ease contributions
fix path
Merge pull request #132 from greg0ire/ease_contributions

fix path
use PSR-4 autoloading

It makes paths less long.
Merge pull request #133 from greg0ire/psr-4

use PSR-4 autoloading
whitespace
rename listener to subscriber
prefer stable packages

They do not take forever to install.
Merge pull request #134 from greg0ire/backwards-compatible

rename listener to subscriber
spelling
rename listener with subscriber when appropriate
Merge pull request #135 from greg0ire/backwards-compatible

Replace most occurences of listener with subscribers