Support SHA512 as hashing algorithm (#8)

security/sha512_test.go

@@ -0,0 +1,12 @@
+package security
+
+import "testing"
+
+func TestSha512(t *testing.T) {
+	input := "password"
+	expectedHash := "b109f3bbbc244eb82441917ed06d618b9008dd09b3befd1b5e07394c706a8bb980b1d7785e5976ec049b46df5f1326af5a2ea6d103fd07c95385ffab0cacbc86"
+	hash := Sha512(input)
+	if hash != expectedHash {
+		t.Errorf("Expected hash to be '%s', but was '%s'", expectedHash, hash)
+	}
+}