Remove duplicate key in yaml header

Author: qinezh

azureps-cmdlets-docs/ResourceManager/docs-conceptual/authenticate-azureps.md

@@ -10,7 +10,6 @@ ms.service: powershell
 ms.devlang: powershell
 ms.topic: conceptual
 ms.date: 03/30/2017
-ms.author: sewhee
 ---
 
 # Log in with Azure PowerShell
@@ -69,4 +68,4 @@ Azure PowerShell cmdlets for role management
 * [New-AzureRmRoleDefinition](/powershell/AzureRM.Resources/New-AzureRmRoleDefinition)
 * [Remove-AzureRmRoleAssignment](/powershell//AzureRM.Resources/Remove-AzureRmRoleAssignment)
 * [Remove-AzureRmRoleDefinition](/powershell//AzureRM.Resources/Remove-AzureRmRoleDefinition)
-* [Set-AzureRmRoleDefinition](/powershell/AzureRM.Resources/Set-AzureRmRoleDefinition)
+* [Set-AzureRmRoleDefinition](/powershell/AzureRM.Resources/Set-AzureRmRoleDefinition)