Upgrade to 1.0.10

Concerns: pushword/admin

The admin elevation ramp has four levels again

--pw-elevation-2 is the card shadow, and the two deep steps moved up one: dropdowns and popovers are --pw-elevation-3, modals and lightboxes --pw-elevation-4.

Affects sites using the elevation properties in their own admin CSS. A rule written against --pw-elevation-3 for a modal now casts the dropdown shadow — shift it to --pw-elevation-4.