Remove uncalled code

Closes #6

Author: Mark Rydstrom

source/Octodiff/Core/ISignatureWriter.cs

@@ -4,7 +4,7 @@ namespace Octodiff.Core
 {
     public interface ISignatureWriter
     {
-        void WriteMetadata(IHashAlgorithm hashAlgorithm, IRollingChecksum rollingChecksumAlgorithm, byte[] hash);
+        void WriteMetadata(IHashAlgorithm hashAlgorithm, IRollingChecksum rollingChecksumAlgorithm);
         void WriteChunk(ChunkSignature signature);
     }
 
@@ -17,7 +17,7 @@ public SignatureWriter(Stream signatureStream)
             this.signatureStream = new BinaryWriter(signatureStream);
         }
 
-        public void WriteMetadata(IHashAlgorithm hashAlgorithm, IRollingChecksum rollingChecksumAlgorithm, byte[] hash)
+        public void WriteMetadata(IHashAlgorithm hashAlgorithm, IRollingChecksum rollingChecksumAlgorithm)
         {
             signatureStream.Write(BinaryFormat.SignatureHeader);
             signatureStream.Write(BinaryFormat.Version);

source/Octodiff/Core/SignatureBuilder.cs

@@ -49,9 +49,7 @@ void WriteMetadata(Stream stream, ISignatureWriter signatureWriter)
             ProgressReporter.ReportProgress("Hashing file", 0, stream.Length);
             stream.Seek(0, SeekOrigin.Begin);
 
-            var hash = HashAlgorithm.ComputeHash(stream);
-
-            signatureWriter.WriteMetadata(HashAlgorithm, RollingChecksumAlgorithm, hash);
+            signatureWriter.WriteMetadata(HashAlgorithm, RollingChecksumAlgorithm);
 
             ProgressReporter.ReportProgress("Hashing file", stream.Length, stream.Length);
         }