Added auto-mapping for complimentary_plan column

closes https://github.com/TryGhost/Team/issues/1076
refs f068e40723
refs 7fe9e06c4d

- The Members CSV importer was not auto-detecting and mapping the `complimentary_plan` column when it was present in CSV. This was to improve user-experience and NOT start the import as a "background job" by default.
- With resent (see refs) changes having "complimentary_plan" column in the imported file does not send the import into the background. We can now safely include it as auto-detected field, without compromising user experience.

ghost/admin/app/services/member-import-validator.js

@@ -82,6 +82,7 @@ export default class MemberImportValidatorService extends Service {
             'name',
             'note',
             'subscribed_to_emails',
+            'complimentary_plan',
             'labels',
             'created_at'
         ];