Description:

This allows you to automatically upgrade selected prerequisites to
selected versions, if, and only if, they're already prerequisites.

This is intended to be used to compliment "[AutoPrereqs]" without adding
dependencies.

[AutoPrereqs]

[Prereqs::Upgrade]
Moose = 2.0 ; Moose 2.0 is added as a minimum to runtime.recommends to
2.0 if a lower version is in runtime.requires

This is intended to be especially helpful in "PluginBundle"'s where one
may habitually always want a certain version of a certain dependency
every time they use it, but don't want to be burdened with remembering
to encode that version of it.