Add Location History handler

[MeurillonGuillaume]

She's finally here!

The long awaited Google Location History file processor. For context, see issue #6.

Code can still use some cleanups though, such as adding the structs from location-history-handler.go into the go-bike-data-lib.

Let me know what you think! 🎉

[antoinerichez]

Looks fine to me, except for the date (is it particularly chosen or just a random one to give the format to use?)