Add LayersTestCase.
Add LayersTestCase.

isaacs/tilemill,Zhao-Qi/tilemill,florianf/tileoven,paulovieira/tilemill-clima,isaacs/tilemill,MappingKat/tilemill,paulovieira/tilemill-clima,MappingKat/tilemill,makinacorpus/tilemill,paulovieira/tilemill-clima,nyimbi/tilemill,nyimbi/tilemill,Zhao-Qi/tilemill,Zhao-Qi/tilemill,mbrukman/tilemill,paulovieira/tilemill-clima,mbrukman/tilemill,fxtentacle/tilemill,makinacorpus/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,tizzybec/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,nyimbi/tilemill,tilemill-project/tilemill,mbrukman/tilemill,nyimbi/tilemill,fxtentacle/tilemill,nyimbi/tilemill,fxtentacle/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,mbrukman/tilemill,tizzybec/tilemill,MappingKat/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,tizzybec/tilemill,paulovieira/tilemill-clima,tizzybec/tilemill,Zhao-Qi/tilemill,MappingKat/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,Zhao-Qi/tilemill,fxtentacle/tilemill,tilemill-project/tilemill,tilemill-project/tilemill,fxtentacle/tilemill,mbrukman/tilemill,tizzybec/tilemill,florianf/tileoven,florianf/tileoven,MappingKat/tilemill,isaacs/tilemill