fix working on python3 project (non odoo case) (#3)

odoo_report_testing/reports.py

@@ -70,7 +70,7 @@ def files_equals(ref, compared, output):
         try:
             p.wait()
             _, err = p.communicate()
-            if err.strip().split('\n')[-1] == '0':
+            if err.decode('utf-8').strip().split('\n')[-1] == '0':
                 equal = True
         except Exception as err:
             p.kill()