Get-Credential throws exception when credential not already stored

[corbob]

Get-Credential is trying to load a credential object even if it's not been stored yet. This causes an exception to be thrown.

May be related to #9 as well.

If we wrap module Line 351 with setting ErrorActionPreference to SilentlyContinue it seems that this would resolve it.

Alternately I imagine changing the CredentialManagement.Store class function Load() to not throw an exception on line 198 might be the more elegant solution.