Add opt outs

[moretonb]

Adds the ability to get and create opt out resources.

Includes some changes and improvements to the existing tests to increase coverage for regression protection.

Usage:

• Create an instance of the optout service

  UserPassword userPassword = new UserPassword("YourUsername","YourPassword");
  BasicServiceFactory serviceFactory = ServiceFactory.createBasicAuthenticatingFactory(userPassword);
  
  OptOutService optOutService = serviceFactory.getOptOutService();

• Get single opt out

  OptOutResponse optout = optOutService.getOptOut("b6a39581-9cfc-40ea-9b40-9320444cf49d");

• Get paged opt outs

  OptOutCollectionResponse optouts = optOutService.getOptOuts(1, 15);

• Create an opt out

  FromAddress fromAddress = new FromAddress();
  fromAddress.setPhoneNumber("99887744556322");
  
  OptOutRequest request = new OptOutRequestImpl();
  request.setAccountReference("EX006789");
  request.setFromAddress(fromAddress);
  
  OptOutResponse optout = optOutService.createOptOut(request);