hepspec weight schema integer fix

Pig schema defined hepspec weights as integers, but the underlying tuples (in MyUDF.SiteAvailability) stored String objects.

Due to that the hepspec weights persisted as strings during the final output in MongoDB.

With fix 2c7a2b4b081ab9d6d8397ff3ed8330962968adef
 weight tuples now contain parsed integers and they persist as integers in MongoDB as well.