rest: remove PATCH schemas
rest: remove PATCH schemas

The REST API currently puts a lot of constraint and difference between
resource creation and update. I don't think it's currently a
requirement, and that complicates a lot of the code of resource
declaration by duplicating their fields.

This patches makes use of new voluptuous feature that allow us to use
the same resource schema for both creation and update of a resource.

Change-Id: I9a5f6f003f13122188324701d297f22628c19fdf

leandroreox/gnocchi,gnocchixyz/gnocchi,gnocchixyz/gnocchi,idegtiarov/gnocchi-rep,idegtiarov/gnocchi-rep,sileht/gnocchi,leandroreox/gnocchi,idegtiarov/gnocchi-rep,sileht/gnocchi