Refactor fo the SSH class.

Fixed some bugs in the initial development.
Added the ping test into the inter vmconnectivity test
Refactor of the ssh modifications

Cleaned the codded, added comments, and improved the readability.
several changes of formating to turn the code flake8 compliant
Merge pull request #5 from alvico/fix_rebase

Refactor for the SSH class.
Test advanced_inter_vmconnectivity (QA263)

Added the the test described on QA263 issue,
touching also scenario.py for adding custom
routers to subnetworks
Ammended the comments from Daniel's Code-Review
Merge pull request #6 from alvico/test-QA263-rebase

Test advanced_inter_vmconnectivity (QA263)
Test QA264 DHCP lease with routes

Added the set of tests to check DHCP lease, routes and dns setup
Modifications fo older tests

In order to make them fully compatible with the new requirements of the
scenario builder.
Fixed inter vm connectivity test

Corrected a bug in the test, due to the change in how
networks are created now.
Merge pull request #7 from alvico/rebase_QA-264

Test QA264 DHCP lease with routes