sorry folks 1.8.7 is just simply a no-go
Page Breaks - round one

This sets up the basic col and row break creation and serialization.
You can specify either a string reference like "C7" or provide an
Axlsx::Cell instance to specify the break point.

Serialization is working cleanly but excel does not automatically
render those breaks yet. You need to switch to page preview mode.
Fixes for anchor swapping when adding images. - Two -> One swap still pending.
repair pivot table data ref populate and bring coverage back up to 100%