New: Fast Deployment

src/GraphDeployer/HashUtil.cs

+using System.Security.Cryptography;
+
+namespace Coscine.GraphDeployer
+{
+    public static class HashUtil
+    {
+        public static string GetFileHash(string path)
+        {
+            using (SHA256 sha256 = SHA256.Create())
+            {
+                using (FileStream fileStream = File.OpenRead(path))
+                {
+                    return BitConverter.ToString(sha256.ComputeHash(fileStream));
+                }
+            }
+        }
+    }
+}