SFML convention is to only use "" includes when the header is in
the same directory as the file including it. Because these test
util headers are in a separate directory, it makes more sense to
include them via <>.
Both ApproxVec and ApproxDeg accept a double then convert that to
a float just to then convert it back to a double. We can save an
extra lossy conversion by just accepting a float instead of a double
in the first place.
