Initial Implementation of check_availability command

In WWW::LogicBoxes
  Modified to consume WWW::LogicBoxes::Role::Command::CheckAvailability

Created WWW::LogicBoxes::Domain
  This is just the base implementation and I intend on expand it before
  releasing it.

In WWW::LogicBoxes::Role::Command::CheckAvailability
  Implemented check_availability method
  Added POD

In t/01-check_availability.t
  Added tests for use cases:
    Single SLD - Single TLD - Available
    Single SLD - Single TLD - Not Available
    Single SLD - Multiple TLD - Available
    Single SLD - Multiple TLD - Not Available
    Multiple SLD - Single TLD - Available
    Multiple SLD - Single TLD - Not Available
    Multiple SLD - Multiple TLD - Available
    Multiple SLD - Multiple TLD - Not Available