Adding a note about 'type' field becoming required in rax_dns_record

library/cloud/rax_dns_record

@@ -82,6 +82,7 @@ notes:
     the Rackspace CloudDNS API"
   - To manipulate a C(PTR) record either C(loadbalancer) or C(server) must be
     supplied
+  - As of version 1.7, the C(type) field is required and no longer defaults to an C(A) record.
   - C(PTR) record support was added in version 1.7
 author: Matt Martz
 extends_documentation_fragment: rackspace