Remove autorest -g install from readme.

readme.md

@@ -4,7 +4,6 @@
 ## Setup
 - [NodeJS](https://nodejs.org/en/) (13.x.x)
 - `npm install` (at root)
-- `npm install -g @autorest/autorest`
 - [.NET Core SDK](https://dotnet.microsoft.com/download/dotnet-core/3.0) (3.0.100)
 - [PowerShell Core](https://github.com/PowerShell/PowerShell/releases/latest)
 - [Java](https://www.java.com/en/download/) (for V2 testserver)