Support Fabric 2.0

[liorko87]

Today only one protocol can be executed due to fabric v1 limits.
The new fabric implementation (v2) can support execution of more then one protocol.

Affected files

• Execution/end_to_end.py
• Execution/fabfile.py

[liorko87]

Since Fabric 2.0 does not support different configuration for each server, the feature on hold.