Reworked SPT tests for running at MOS inside rally pod

These SPT tests are taken from the CVP-SPT, but reworked
to test MOS inside rally pod.

Here is the list of changes since CVP-SPT:
* Switched to Python3
* Removed all Salt related code
* Removed HW2HW test
* Default global_config.yaml is suitable for MOS
* Switched to iperf3
* Added smart waiters for VMs to be Active, VMs to be reachable by FIPs
* Extended pytest.ini file with logging settings
* Added lots of loggers at info level to understand what happends during the test run
* Extended & fixed README with the actual instruction
* Ability to use iperf3 even if there is no Internet at VMs
* Fixed the coding style according PEP8
* Various small fixes, enhancements

Change-Id: I31a1b8c8c827133d144377031c6f546d8c82a47d
diff --git a/conftest.py b/conftest.py
new file mode 100644
index 0000000..693d514
--- /dev/null
+++ b/conftest.py
@@ -0,0 +1 @@
+from fixtures.base import *