Remove python3.4 from tox
Remove python3.4 from tox

The Consistent Testing Interface (CTI) [1] does not list python3.4
testing as needed for OpenStack Python 3 support.  This patch removes
the unnecessary Python 3.4 tests from our tox configuration.

[1] https://governance.openstack.org/tc/reference/cti/python_cti.html

Change-Id: I4d9b72f7ad83c4d41ce364a1d0253c358537e64c

openstack/octavia,openstack/octavia,openstack/octavia