Create a new customer application.

Applications can hold more data than just the standard Bud Customer
information, such as:

• Applicant First Name
• Applicant Last Name
• Names for Secondary Applicants (if this is a joint application)
• Key-value pairs for additional metadata you may want to associate to
  this application (e.g. if the customer is applying for finance, your
  system may have a product code for the relevant finance product).