Fix 'Add getting logs from jobs'

convert asci to unicode

Related-Prod: PROD-36500
Change-Id: I1a9647546a5590bbfa2b2863010c76a67182d59e
diff --git a/tcp_tests/managers/drivetrain_manager.py b/tcp_tests/managers/drivetrain_manager.py
index 2f23df2..df2798f 100644
--- a/tcp_tests/managers/drivetrain_manager.py
+++ b/tcp_tests/managers/drivetrain_manager.py
@@ -91,7 +91,7 @@
         job_log = jenkins.get_build_output(job_name, build_number)
 
         with open('tmp/' + job_name + str(build_number) + '.log', 'wb') as f:
-            f.write(job_log)
+            f.write(job_log.encode('utf-8'))
 
         if job_result != 'SUCCESS':
             LOG.warning("{0}\n{1}".format(description, '\n'.join(stages)))