Show message if the install directory doesn't exist and it needs to be created.
Show message if the install directory doesn't exist and it needs to be created.

yugangw-msft/azure-cli,BurtBiel/azure-cli,yugangw-msft/azure-cli,yugangw-msft/azure-cli,samedder/azure-cli,QingChenmsft/azure-cli,yugangw-msft/azure-cli,QingChenmsft/azure-cli,QingChenmsft/azure-cli,QingChenmsft/azure-cli,samedder/azure-cli,samedder/azure-cli,yugangw-msft/azure-cli,yugangw-msft/azure-cli,samedder/azure-cli,BurtBiel/azure-cli