Remove information about update on PSCore 6.0.x - Pester is not bundl…

…ed since 6.0.0-rc2 (pester#962)

README.md

@@ -1,6 +1,6 @@
 # Pester
 
-> Pester [4.1.0](https://github.com/pester/Pester/releases/tag/4.1.0) now runs on Linux and macOS! 🎉 🍾 
+> Pester [4.1.0](https://github.com/pester/Pester/releases/tag/4.1.0) now runs on Linux and macOS! 🎉 🍾
 
 Pester is the ubiquitous test and mock framework for PowerShell.
 
@@ -67,12 +67,6 @@ Install-Module -Name Pester -Force -SkipPublisherCheck
 
 Not running Windows 10 or facing problems? See the [full installation and update guide](https://github.com/pester/Pester/wiki/Installation-and-Update).
 
-Please be aware that PowerShell Core 6.0.0-beta.9 comes with bundle Pester version 3.3.9, but we recommend updating, by running this PowerShell command _as administrator_:
-
-```powershell
-Install-Module -Name Pester -Force
-```
-
 ## Features
 
 ### Test runner