Modify requirement list

Signed-off-by: NXu Han <xuhan@redhat.com>

requirements-travis.txt

-coverage==3.6
-nose==1.3.0
-nosexcover==1.0.8
-tox==1.5.0
 virtualenv==1.9.1
 simplejson==3.8.1
-MySQL-python==1.2.5
 inspektor==0.4.5
-autotest==0.16.2
+autotest==0.16.2; python_version < '3.0'

requirements.txt

-coverage==3.6
-nose==1.3.0
-nosexcover==1.0.8
-tox==1.5.0
 virtualenv==1.9.1