update version

Author: inwoods

Assets/FbxExporters/README.txt

@@ -5,9 +5,9 @@ Copyright (c) 2017 Unity Technologies. All rights reserved.
 Licensed under the ##LICENSENAME##.
 See LICENSE.md file for full license information.
 
-**Version**: 0.0.3a
+**Version**: 0.0.4a
 
 Requirements
 ------------
 
-* [FBX SDK C# Bindings v0.0.3a or higher](https://github.com/Unity-Technologies/FbxSharp)
+* [FBX SDK C# Bindings v0.0.4a or higher](https://github.com/Unity-Technologies/FbxSharp)