add upstart script

miscellaneous/agentdriver.conf

+description "CIRCLE agentdriver"
+
+start on runlevel [2345]
+stop on runlevel [!2345]
+
+respawn
+respawn limit 30 30
+setgid cloud
+setuid cloud
+
+
+script
+    cd /home/cloud/agentdriver
+    . /home/cloud/.virtualenvs/agentdriver/local/bin/activate
+    . /home/cloud/.virtualenvs/agentdriver/local/bin/postactivate
+    python agentdriver.py
+end script