dbt_includes flag should be case insensitive

[leoebfolsom]

dbt model names are case insensitive, and so the user should be able to enter the names of included models in lowercase, which is often how models are typed.

Currently, because model_name in dbt_manifest.py is uppercased, model names that are sent to the includes variable as lowercase strings are ignored.

A simple uppercasing of the includes list solves this.

I'll open a PR.

Note: I think a similar issue may exist with dbt_excludes, but I don't need to use that at the moment, and when I tried to include it as a quick fix, it didn't work expected and I don't have time to dig into it, so I'm leaving it for now.