tests: replace "from util import *" by explicit imports

tests/test_searchadapters.py

@@ -9,15 +9,13 @@
     :license: BSD, see LICENSE for details.
 """
 
-import os, sys
+import os
 from StringIO import StringIO
 
-from nose import SkipTest
-
 from sphinx.websupport import WebSupport
 
 from test_websupport import sqlalchemy_missing
-from util import *
+from util import test_root, skip_if, skip_unless_importable
 
 
 def clear_builddir():