Adding missing imports

Author: bsipocz

astroquery/cosmosim/core.py

@@ -9,6 +9,8 @@
 import time
 import smtplib
 import re
+import os
+import threading
 from six.moves.email_mime_multipart import MIMEMultipart
 from six.moves.email_mime_base import MIMEBase, message
 from six.moves.email_mime_text import MIMEText