Changes related to azure-cli in kudu service

Has the following changes:
- Web.config generation for node websites moved from deployment script generation to execution (inside selectNodeVersion.js).
- Updated azure-cli to be based on recent release.

Related change in azure-cli (specific for kudu for now):
https://github.com/amitapl/azure-sdk-tools-xplat/commit/c5f17f3591b0de2a8db33e3bc156f55afd793a04

azure-cli branch we use:
https://github.com/amitapl/azure-sdk-tools-xplat/commits/kudu_s21

NOTE: Still require test in Azure (currently is being done).