Previous tag as dynamic base revision

[pvicente]

Orb version:

1.0.0

What happened:

In my deployments I'm using tags to go to production, I want to use previous deployed tag to filter changes in my monorepo,
with something the execution of something like git tag --sort=-creatordate | head -n 2 | tail -n 1 but currently this parameter cannot be dynamic.

Expected behavior:

Able to specify dynamic base revision.

I can see this PR that could add this support.