upgrade tegola to latest version
Currently we cannot upgrade due to https://github.com/go-spatial/tegola/issues/559.
Nice to have fix: https://github.com/go-spatial/tegola/issues/539
Edited by Gautier P
Currently we cannot upgrade due to https://github.com/go-spatial/tegola/issues/559.
Nice to have fix: https://github.com/go-spatial/tegola/issues/539