OVERVIEW
This is a little program that interacts with the USPS address validation API.
You give it JSON and this will give you cleaned-up JSON.

You will need to sign up with the USPS folks and have them give you logins.
If you are working with their test environment, modify the SITE and API_URL constants below.

Given this JSON string over STDIN:
  {
    "address1": "771 Encina",
    "address2": "",
    "city":     "Gilbert",
    "state":    "AZ",
    "zip":      ""
  }

 Will spit out this cleaned up JSON:
   {
     "address1": "771 E ENCINAS AVE",
     "address2": "",
     "city":     "GILBERT",
     "state":    "AZ"
     "zip":      "85234",
     "success":  true,
   }

 If USPS can't find the address, it'll output something like:
   {
     "error_message": "Address Not Found.",
     "success":       false
   }