Update for MAPI testing

Update connection.py 
 - modify createSecurityGroup function's argrment for testing more flexible

Update securitygroup.py 
 - init menber should be empty list instead of none

Update keyrequest.py 
 - add four functions for some testing

Update instance.py 
 - add encrypt a vm function for some testing
 - add createRAID function's arguments for testing more flexible

Update device.py 
 - add update function for "update raid" testing