testProductSchema() was failing because the order of the properties were not matching the order specified by the json-schema.org product schema. It would be nice if we generate the properties in order. Put in a simple fix where methods are ordered by name. This fixes the test and produces consistent schema.

Added syntax highlight to sample code in README.
Spotted another instance where ordering was not specified. Fixed.
Merge pull request #22 from aruld/master

Ordering the schema properties