Fix sha256 hashing. Fix v2 lookup.

src/test/java/io/kamax/mxisd/test/hash/HashEngineTest.java

@@ -0,0 +1,15 @@
+package io.kamax.mxisd.test.hash;
+
+import static org.junit.Assert.assertEquals;
+
+import org.apache.commons.codec.digest.DigestUtils;
+import org.junit.Test;
+
+public class HashEngineTest {
+
+    @Test
+    public void sha256test() {
+        assertEquals("a26de61ae3055f84b33ac1a179b9ad5301f9109024f4db1ae653ea525d2136f4",
+            DigestUtils.sha256Hex("user2@mail.homeserver.tld email I9x4vpcWjqp9X8iiOY4a"));
+    }
+}