Project replaces fix for rpms

I was having trouble getting an omnibus rpm I made to upgrade when I had renamed it. It seems like this is what `replaces` is for in the omnibus project. After reading around various places, including [The Fedora project's guidelines for renaming/replacing packages](https://fedoraproject.org/wiki/Packaging:Guidelines#Renaming.2FReplacing_Existing_Packages), it seems like `replaces` (not `conflicts`) should be used for the `Obsoletes:` entries in the rpm package specs.