[material graph]Fix test name

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Editor/Testing/UnitTests/SerializedGraphTests.cs

 namespace UnityEditor.Graphing.UnitTests
 {
     [TestFixture]
-    public class ScriptableGraphTests
+    public class SerializableGraphTests
     {
         [TestFixtureSetUp]
         public void RunBeforeAnyTests()