Use deep_merge on chained additional_params

Author: tom-lord

lib/json_api_client/query/builder.rb

@@ -136,7 +136,7 @@ def _new_scope( opts = {} )
              primary_key:       opts.fetch( :primary_key, @primary_key ),
              pagination_params: @pagination_params.merge( opts.fetch( :pagination_params, {} ) ),
              path_params:       @path_params.merge( opts.fetch( :path_params, {} ) ),
-             additional_params: @additional_params.merge( opts.fetch( :additional_params, {} ) ),
+             additional_params: @additional_params.deep_merge( opts.fetch( :additional_params, {} ) ),
              filters:           @filters.merge( opts.fetch( :filters, {} ) ),
              includes:          @includes + opts.fetch( :includes, [] ),
              orders:            @orders + opts.fetch( :orders, [] ),