Fix sed invocation for use on MacOS

Author: kgryte

tools/scripts/npm_publish

@@ -258,7 +258,7 @@ update_markdown_package_urls() {
 # Updates the version in the root package.json.
 update_version() {
 	echo 'Updating project version...' >&2
-	sed -i "s/${current_version}/${release_version}/" "${package_json}"
+	sed -i '' "s/${current_version}/${release_version}/" "${package_json}"
 	if [[ "$?" -ne 0 ]]; then
 		echo '' >&2
 		echo 'Error: unexpected error. Encountered an error when updating project version.' >&2