Changed lume.round() such that 0 results in 0 rather than -0

lume.lua

@@ -78,7 +78,7 @@ end
 
 function lume.round(x, increment)
   if increment then return lume.round(x / increment) * increment end
-  return x > 0 and math_floor(x + .5) or math_ceil(x - .5)
+  return x >= 0 and math_floor(x + .5) or math_ceil(x - .5)
 end