Add test for grid iteration.

kmath-for-real/src/commonTest/kotlin/kaceince/kmath/real/GridTest.kt

@@ -15,4 +15,13 @@ class GridTest {
         assertEquals(6, grid.size)
         assertTrue { (grid - DoubleVector(0.0, 0.2, 0.4, 0.6, 0.8, 1.0)).norm < 1e-4 }
     }
+
+    @Test
+    fun testIterateGrid(){
+        var res = 0.0
+        for(d in 0.0..1.0 step 0.2){
+            res = d
+        }
+        assertEquals(1.0, res)
+    }
 }