Moved legacy tests into tests

tests/runtests.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python2.7
+# Copyright 2018-2021 XMOS LIMITED.
+# This Software is subject to the terms of the XMOS Public Licence: Version 1.
+import xmostest
+import os.path
+
+if __name__ == "__main__":
+
+
+    xmostest.init()
+
+    xmostest.register_group("lib_xua",
+                            "i2s_loopback_sim_tests",
+                            "I2S loopback simulator tests",
+
+    """
+Tests are performed by running the audiohub code connected to a 
+loopback plugin 
+""")
+
+    xmostest.runtests()
+
+    xmostest.finish()