Unicorn long-since lost most of its use, due to dynarmic gaining support for handling most instructions. At this point any further issues encountered should be used to make dynarmic better. This also allows us to remove our dependency on Python.
Port citra-emu/citra#4215: "travis: Use Ninja for Travis builds"
* travis: use prebuilt image * travis: use prebuilt image (MinGW)
This commit also fixed a broken cmake dependency with unicorn