Updated ChangeLog.md

Author: gkostal

src/Attestation/Attestation/ChangeLog.md

@@ -22,6 +22,7 @@
 ## Upcoming Release
 * Added policy signer management cmdlets to `Az.Attestation` module
 * Added `Location` and `Tag` to `New-AzAttestation`
+* Added three additional required assemblies to Az.Attestation.psd1
 
 ## Version 0.1.4
 * Added policy management cmdlets to `Az.Attestation` module