removed 'preview' from windows 2019 and ubuntu 18.04

Author: shivanissambare

articles/machine-learning/data-science-virtual-machine/provision-vm.md

@@ -27,7 +27,7 @@ Please note Azure free accounts do not support GPU enabled virtual machine SKUs.
 To create a DSVM instance:
 
 1. Go to the [Azure portal](https://portal.azure.com) You might be prompted to sign in to your Azure account if you're not already signed in.
-1. Find the virtual machine listing by typing in "data science virtual machine" and selecting "Data Science Virtual Machine - Win 2019 (Preview)."
+1. Find the virtual machine listing by typing in "data science virtual machine" and selecting "Data Science Virtual Machine - Windows 2019."
 
 1. Select the **Create** button at the bottom.