some changes to run tests on linux
diff --git a/tests/all_tests.py b/tests/all_tests.py
old mode 100644
new mode 100755
index 0ed455c..6da60b8
--- a/tests/all_tests.py
+++ b/tests/all_tests.py
@@ -1,5 +1,8 @@
 #!/usr/bin/env python
 
+import sys
+sys.path.extend(['.', '..'])
+
 import unittest