1. Added packages_dev.xml in contrail-webui-third-party repo which lists the dependencies for dev&test environment and used in for "make dev-env" target
Removed fetch_packages.sh script and instead use fetch_packages.py

2. Using packages_dev.xml file for downloading the dev dependencies using
fetch_packages.py script

Change-Id: I1ea6a04a71bc2705a85c8260bdec7707fb28eb34
Merge "1. Added packages_dev.xml in contrail-webui-third-party repo which lists the dependencies for dev&test environment and used in for "make dev-env" target Removed fetch_packages.sh script and instead use fetch_packages.py"