Update README.md

Use standard module imports

Author: pappleby64

Usage/README.md

@@ -1,8 +1,9 @@
-# Azure Stack Usage 
+As a prerequisite, make sure that you installed the correct PowerShell modules and versions:
 
 ```powershell
-Install-Module -Name AzureRM -RequiredVersion 1.2.8 -Scope CurrentUser
-Install-Module -Name AzureStack -RequiredVersion 1.2.8 -Scope CurrentUser
+Install-Module -Name 'AzureRm.Bootstrapper' -Scope CurrentUser
+Install-AzureRmProfile -profile '2017-03-09-profile' -Force -Scope CurrentUser
+Install-Module -Name AzureStack -RequiredVersion 1.2.9 -Scope CurrentUser
 ```
 ```
 Use this script to extract usage data from the AzureStack Usage API's and export it to a CSV file