Remove exit(1) when no files found to scan (#64)

* fix the process exit when hanlding the loop cases

* use throw exception instead

src/run.js

@@ -31,7 +31,7 @@ async function run({
 
   if (files.length === 0) {
     console.error(`No files found to scan.`);
-    process.exit(1);
+    throw new Error(`No files found to scan.`);
   }
 
   let report = {};