The tileset `test` does not exist，bug it is exist, because of / and \ in window

[hemincan]

cesium-terrain-server -dir F:\data\tilesets -port 8081

[hemincan]

cesium-terrain-server -dir F:\data\tilesets -port 8081 is not work,
but cesium-terrain-server -dir F:/data/tilesets -port 8081 is work.......................................................