Better way of finding xmlsec1 binaries

tests/conftest.py

@@ -0,0 +1,9 @@
+import os
+    
+def pytest_funcarg__xmlsec(request):
+    for path in os.environ["PATH"].split(":"):
+        fil = os.path.join(path, "xmlsec1")
+        if os.access(fil,os.X_OK):
+            return fil
+
+    raise Exception("Can't find xmlsec1")