add script to invalidate cache.

This maybe should be a default part of publish, but
I haven't decided if it is a good idea..  It could be
configuratable.

invalidate.py

@@ -0,0 +1,32 @@
+import boto.cloudfront
+import os
+import time
+
+if __name__ == '__main__':
+	key = os.environ['AWS_ACCESS_KEY_ID']
+	secret = os.environ['AWS_SECRET_ACCESS_KEY']
+	distid = os.environ['BAYSEC_DISTID']
+
+	c = boto.cloudfront.CloudFrontConnection(key, secret)
+
+	#help(c)
+
+	#print(list(c.get_invalidation_requests(distid)))
+
+	iq = c.create_invalidation_request(distid, [ '/*' ])
+	iqid = iq.id
+
+	print('invalidation id:', iqid)
+
+	for i in range(20):
+		if iq.status == 'Completed':
+			print('Done')
+			break
+
+		print('checking...')
+		time.sleep(5)
+		iq = c.invalidation_request_status(distid, iqid)
+	else:
+		print('failed, c is connection, iq is last request, iqid is Id of request')
+		import pdb
+		pdb.set_trace()