Use float instead of double for test values

Summary:
Use explicit float values to remove warning.
Closes https://github.com/facebook/yoga/pull/318

Reviewed By: gkassabli

Differential Revision: D4383687

Pulled By: emilsjolander

fbshipit-source-id: a820bf829f74a7bdaefc39e783d03b42e27d0b3b

tests/YGRoundingMeasureFuncTest.cpp

@@ -17,8 +17,8 @@ static YGSize _measureFloor(YGNodeRef node,
   YGMeasureMode heightMode) {
 
   return YGSize{
-    width = 10.2,
-    height = 10.2,
+    width = 10.2f,
+    height = 10.2f,
   };
 }