Run vkcube with performance layers enabled. (#67)
Run vkcube with performance layers enabled. (#67)

After the build was done, the layers were not tested on an actual Vulkan
application.
All the layers are now enabled by getting included in
`VK_INSTANCE_LAYERS`.
By running `vkcube` we check if an application crashes with layers
enabled.
google/vulkan-performance-layers,google/vulkan-performance-layers,google/vulkan-performance-layers