Update to latest tox

This commit updates to the latest tox, it also updates the tox.ini to
use develop instead of sdist/install.

Change-Id: I1ef044a5638be99fc060fd30c1cbd5ea8283e881
Add a create_router utility function

Similary to other neutron resources, add a utility function for
creating a logical router in tempest.api.network.base.BaseNetworkClient

Also, adapt test_floating_ips to use this function

Change-Id: I36f60028f75f7d4b2ed814a965431d2d4138cfbd
Partial-Bug: #1228091
Restores passing additional parameters to nosetest

Parameters after -- are only passed to testr and not to nosetest.
The patch restores the old behaviour.

Change-Id: Ia25b0c071f7292a5ddf34f057b19d03f879dc0af
add more test cases to api/network/security_groups

explicit rule parameters:
create a rule for each protocol (tcp, udp, icmp)

Change-Id: I5adc0d1f2af994031823e19675177566fb3db202
remove tearDownClass in test_quotas.py

There is no need for the functionality of the tearDownClass in the
api/compute/admin/test_quotas.py, becase it's already included in the base
class. So it should be removed.

Change-Id: Ic0e145952cc143d65291258fc9567807ca051596
closes-bug: #1239722
Reduce vm creations in negative tests

In test_server_actions.py, there is a feature that the same server is
used with all test cases. The feature have reduced vm creations.
This patch adds the same feature to negative tests.

Change-Id: I286082e3a8d35bc57049741bedb8026021b653bd
Merge "Reduce vm creations in negative tests"
Merge "Update to latest tox"
Merge "remove tearDownClass in test_quotas.py"
Merge "Restores passing additional parameters to nosetest"
Merge "add more test cases to api/network/security_groups"
Merge "Add a create_router utility function"
Skip get_server_diagnostics test until bug 1240043 is fixed

Change If631472081d16fe8c0b37575eb157a7b13d6fba4 introduced new restrictions
on the diagnostics API which are not valid with XenAPI and causes it to fail
tempest tests.

Bug 1240043 has been raised to define a hypervisor-agnostic API which can be
tested and maintained

Closes bug: 1239209

Change-Id: I3e643d8e7a63b7dc42a912fab09ffc4222d463db