feat: do not crash if package.json doesn't exist

Author: medikoo

lib/private/update-package-json.js

@@ -5,8 +5,12 @@ const { resolve } = require("path")
     , writeFile   = require("fs2/write-file");
 
 const resolveIndentationString = async packageJsonPath => {
-	const match = String(await readFile(packageJsonPath)).match(/^(\s+)[^\s]/u);
-	return (match && match[1]) || "  ";
+	const packageJsonString = await readFile(packageJsonPath, { loose: true, encoding: "utf8" });
+	if (packageJsonString) {
+		const match = packageJsonString.match(/^(\s+)[^\s]/u);
+		if (match) return match[1];
+	}
+	return "  ";
 };
 
 module.exports = async (path, packageJson) => {