Fixes Python34 bugs

This fix is needed due to the different encodings on Python27 and
Python34. Some tests failed and some string values were not
compatible.

Change-Id: I7206a0549051971da76b3b30221aea9f86eed904
Remove deprecated static network config method

Refactor all the services in such way that they support
the new `get_network_details` method instead of the old
`get_network_config` method for statically configuring
network interfaces through the networkconfig plugin.

Change-Id: Idb519935da0d3aee316ad9bc9451f74bc80b12ba