Add-AzureKeyVaultManagedStorageAccount cmdlet not found in AzureRM.KeyVault v. 3.1.0

azure powershell azure-resource-manager azure-keyvault

Here are the steps I would do.

Shutdown all powershell processes or reboot
Go to c:\program files\windowspowershell\modules and delete the folder with the AzureRM.keyvault in name
Launch powershell and install the module Install-Module -Name AzureRM.KeyVault