Remove unnecessary tags/attributes from our tests

Remove the following tags/attributes from our tests:
S3, EC2, slow, bug=lp912922, bug='lp1170718',
category='server-addresses', category='live-migration',
nagative, type='regression'

Now, we are left with:

Tag                   Total # of instances
--------------------  --------------------
'NO TAG'              192
gate                  62
negative              172
positive              110
smoke                 89
whitebox              2

Attribute             Total # of instances
--------------------  --------------------
type                  408

Change-Id: Idab48a7e1a53a3d64fb57ae3cd3975d665180aeb