MapBasedAnyObject.getLong() doesn't work as expected with SnakeYaml loader

[MapBasedAnyObject.getLong()](https://github.com/bigdata-mx/AnyObject/blob/master/src/main/java/mx/bigdata/anyobject/MapBasedAnyObject.java#L80) doesn't work as expected with SnakeYaml loader. 

If the number loaded fits an integer then thats what will be stored in the map and then the cast from Integer to Long fails. Code should review the value and wrap with long as needed
