Fix missing require after merge.

Author: liron-strattic

lib/packageModules.js

@@ -6,6 +6,7 @@ const path = require('path');
 const bestzip = require('bestzip');
 const glob = require('glob');
 const semver = require('semver');
+const fs = require('fs');
 
 function setArtifactPath(funcName, func, artifactPath) {
   const version = this.serverless.getVersion();