implement tests

also fix MD5

src/commonTest/kotlin/com/infendro/hash/keccak/shake/SHAKE256.kt

@@ -0,0 +1,42 @@
+package com.infendro.hash.keccak.shake
+
+import kotlin.test.Test
+import kotlin.test.assertContentEquals
+import kotlin.test.assertEquals
+
+class `SHAKE256 Test` {
+    val function = SHAKE256(64)
+
+    @Test
+    fun `bytes and block`() {
+        assertEquals(64, function.bytes)
+        assertEquals(512, function.bits)
+        assertEquals(136, function.block)
+    }
+
+    @Test
+    fun `empty bytearray`() {
+        val expected = ubyteArrayOf(
+            0x46U, 0xb9U, 0xddU, 0x2bU,
+            0x0bU, 0xa8U, 0x8dU, 0x13U,
+            0x23U, 0x3bU, 0x3fU, 0xebU,
+            0x74U, 0x3eU, 0xebU, 0x24U,
+            0x3fU, 0xcdU, 0x52U, 0xeaU,
+            0x62U, 0xb8U, 0x1bU, 0x82U,
+            0xb5U, 0x0cU, 0x27U, 0x64U,
+            0x6eU, 0xd5U, 0x76U, 0x2fU,
+            0xd7U, 0x5dU, 0xc4U, 0xddU,
+            0xd8U, 0xc0U, 0xf2U, 0x00U,
+            0xcbU, 0x05U, 0x01U, 0x9dU,
+            0x67U, 0xb5U, 0x92U, 0xf6U,
+            0xfcU, 0x82U, 0x1cU, 0x49U,
+            0x47U, 0x9aU, 0xb4U, 0x86U,
+            0x40U, 0x29U, 0x2eU, 0xacU,
+            0xb3U, 0xb7U, 0xc4U, 0xbeU,
+        )
+        val actual = function.hash(
+            ubyteArrayOf()
+        )
+        assertContentEquals(expected, actual)
+    }
+}