What would be the most basic Mac Mini to test LibGDX apps on for iPhone?

I am developing apps for Android using LibGDX, and I would like to publish them for iPhone as well. I do not own a Mac and I heard that a Mac Mini would be a cheap solution to develop for iPhone.

What are the minimum requirements for a Mac Mini to test apps on? I would be primarily developing on Windows, so my idea would be that it's okay if the Mac is not the fastest one. I just need it primarily for testing.

I would like to know the minimum CPU, memory, O/S, and software that is necessary for testing.