Fix billing netcore support

Author: wilcobmsft

src/ResourceManager/Billing/AzureRM.Billing.Netcore.psd1

@@ -72,7 +72,7 @@ NestedModules = @('.\Microsoft.Azure.Commands.Billing.dll')
 FunctionsToExport = @()
 
 # Cmdlets to export from this module, for best performance, do not use wildcards and do not delete the entry, use an empty array if there are no cmdlets to export.
-CmdletsToExport = 'Get-AzureRmBillingInvoice', 'Get-AzureRmBillingPeriod'
+CmdletsToExport = 'Get-AzureRmBillingInvoice', 'Get-AzureRmBillingPeriod', 'Get-AzureRmEnrollmentAccount'
 
 # Variables to export from this module
 # VariablesToExport = @()