tests: update test-pager to pass our import checker

tests: update test-pager to pass our import checker

--- a/tests/test-pager.t	Tue Aug 22 16:58:52 2017 -0400
+++ b/tests/test-pager.t	Tue Aug 22 16:58:57 2017 -0400
@@ -342,7 +342,9 @@
 
 Environment variables like LESS and LV are set automatically:
   $ cat > $TESTTMP/printlesslv.py <<EOF
-  > import os, sys
+  > from __future__ import absolute_import
+  > import os
+  > import sys
   > sys.stdin.read()
   > for name in ['LESS', 'LV']:
   >     sys.stdout.write(('%s=%s\n') % (name, os.environ.get(name, '-')))