Update ol

https://github.com/openlayers/ol3/commit/4e1012823fa87ed713b9636f19e4b904071b1d53
Add tests for the gaLayers service

Some tests were commented out in MapService.spec.js because of https://github.com/openlayers/ol3/pull/860. This PR is now closed so we can have these tests.
Merge pull request #144 from geoadmin/dev_update-ol

Update ol and uncomment gaLayers tests