Remove redundant deprecation warning

This was introduced in 2e19c7a, but the referenced RFC has since been
superceded, and it is now accepted to have a body in a DELETE request.

https://tools.ietf.org/html/rfc7231#page-29

lib/gds_api/base.rb

@@ -23,7 +23,6 @@ def create_client
                           :put_json,
                           :patch_json,
                           :delete_json,
-                          :delete_json_with_params!,
                           :get_raw, :get_raw!,
                           :put_multipart,
                           :post_multipart

lib/gds_api/json_client.rb

@@ -68,18 +68,6 @@ def delete_json(url, params = {}, additional_headers = {})
       do_json_request(:delete, url, params, additional_headers)
     end
 
-    def delete_json_with_params!(url, params, additional_headers = {})
-      warn <<-doc
-        DEPRECATION NOTICE: Delete requests should not include parameters.
-
-        Do not use this method as the ability to do this will be removed.
-
-        Called from: #{caller[2]}
-      doc
-
-      do_json_request(:delete, url, params, additional_headers)
-    end
-
     def post_multipart(url, params)
       r = do_raw_request(:post, url, params.merge(multipart: true))
       Response.new(r)