Boto no longer needs env variables, will check all locations

Boto is now a robust aws sdk and looks for  credentials in the following places (in this order)
 1.Credentials passed into constructor
 2.Environment variables for AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY (what was previously coded)
 3.Named profiles in the ~/.aws/credentials file (as specified)
 4.Default profile in the ~/.aws/credentials files
 5.Named profile in the boto config
 6.Default profile in boto config
 7.Instance profile credentials (if on EC2 instance)

bin/rpm-s3

@@ -43,7 +43,7 @@ class S3Grabber(object):
         base = urlparse.urlsplit(baseurl)
         self.baseurl = baseurl
         self.basepath = base.path.lstrip('/')
-        self.bucket = boto.connect_s3(os.environ['AWS_ACCESS_KEY'], os.environ['AWS_SECRET_KEY']).get_bucket(base.netloc)
+        self.bucket = boto.connect_s3().get_bucket(base.netloc)
         self.visibility = visibility
 
     def check(self, url):