model/tracking: Added elevation column
setup.py: Upgrade geoalchemy2 to 0.2 stable
model/elevation: Added get() classmethod
tracking/server: Add elevation height if location is provided
Merge branch 'master' into elevation

Conflicts:
	skylines/model/elevation.py
	skylines/tracking/server.py
Merge branch 'master' into elevation
Merge pull request #23 from Turbo87/elevation

Adding elevation data to the live tracking