lock on write, use write_atomic
lock on write, use write_atomic

fix test for python 3

drnextgis/mapproxy,vrsource/mapproxy,vrsource/mapproxy,camptocamp/mapproxy,olt/mapproxy,drnextgis/mapproxy,camptocamp/mapproxy,olt/mapproxy,mapproxy/mapproxy,mapproxy/mapproxy