Support for not specifying an S3 object ACL.

config.js

@@ -52,7 +52,7 @@ Options:
 	--s3_force_path_style  Whether to force path style URLs for S3 objects. (default: false)
 	--s3_secret_key <secret>	S3 secret key, required if --s3_endpoint is set. (default: none) 
 	--s3_signature_version <version>	S3 signature version. (default: 4)
-	--s3_acl <canned-acl> S3 object acl. (default: public-read)
+	--s3_acl <canned-acl> S3 object acl. Can specify "none" to skip. (default: public-read)
 	--s3_upload_everything	Upload all task results to S3. (default: upload only all.zip archive)
 	--s3_ignore_ssl Whether to ignore SSL errors while connecting to S3. (default: false)
 	--max_concurrency   <number>	Place a cap on the max-concurrency option to use for each task. (default: no limit)

libs/S3.js

@@ -118,12 +118,17 @@ module.exports = {
                 const filename = path.basename(file.dest);
                 progress[filename] = 0;
 
-                s3.upload({
+                let uploadCfg = {
                     Bucket: bucket,
                     Key: file.dest,
-                    Body: fs.createReadStream(file.src),
-                    ACL: config.s3ACL
-                }, {partSize, queueSize: concurrency}, err => {
+                    Body: fs.createReadStream(file.src)
+                }
+                
+                if (config.s3ACL != "none") {
+					uploadCfg.ACL = config.s3ACL;
+				}
+
+                s3.upload(uploadCfg, {partSize, queueSize: concurrency}, err => {
                     if (err){
                         logger.debug(err);
                         const msg = `Cannot upload file to S3: ${err.message} (${err.code}), retrying... ${file.retries}`;