BrainEditor: Replaced `new SerializedObject()` with property. (#88)

* Fixed `Academy` children `Brain` gathering.

* Brain-Editor: Replaced `new SerializedObject()` with `serializedObject`.

* BrainEditor: Simplified `if` condition for `BrainParameters` checks.

unity-environment/Assets/ML-Agents/Editor/BrainEditor.cs

 [CustomEditor (typeof(Brain))]
 public class BrainEditor : Editor
 {
-	
-
-		SerializedObject serializedBrain = new SerializedObject (target);
+		SerializedObject serializedBrain = serializedObject;
 
 		if (myBrain.transform.parent == null) {
 			EditorGUILayout.HelpBox ("A Brain GameObject must be a child of an Academy GameObject!", MessageType.Error);
 
-
+		BrainParameters parameters = myBrain.brainParameters;
+		if (parameters.actionDescriptions == null || parameters.actionDescriptions.Length != parameters.actionSize)
+			parameters.actionDescriptions = new string[parameters.actionSize];
+		
+		serializedBrain.Update();
+		
-		if (myBrain.brainParameters.actionDescriptions == null) {
-			myBrain.brainParameters.actionDescriptions = new string[myBrain.brainParameters.actionSize];
-		}
-		if (myBrain.brainParameters.actionSize != myBrain.brainParameters.actionDescriptions.Count()) {
-			myBrain.brainParameters.actionDescriptions = new string[myBrain.brainParameters.actionSize];
-		}
-		serializedBrain.Update();
 		EditorGUILayout.PropertyField(bp, true);
 
 		SerializedProperty bt = serializedBrain.FindProperty("brainType");
 		serializedBrain.ApplyModifiedProperties();
 
 		myBrain.UpdateCoreBrains ();
-
-
-
 	}
 }