Update CHANGELOG

CHANGELOG

@@ -1,8 +1,7 @@
 0.7.2
-- Adds typealias PKCS5.Padding()
 - Adds Padding enum (.pkcs5, .pkcs7, .noPadding, .zeroPadding)
-- Remove Generics from the public API
-- Improve SHA1, SHA2, SHA3 performance by using unmanaged buffers.
+- Removes Generics from the public API.
+- Slightly improves SHA1, SHA2, SHA3 performance.
 
 0.7.1
 - Swift 4.0 compatibility release