Bug 1559975 - fix python2 linter errors for testing/runtimes r=ahal

Differential Revision: https://phabricator.services.mozilla.com/D37615

--HG--
extra : moz-landing-system : lando

testing/runtimes/writeruntimes.py

@@ -1,4 +1,7 @@
 #!/usr/bin/env python
+
+from __future__ import absolute_import, print_function
+
 from argparse import ArgumentParser
 from collections import defaultdict
 import datetime

tools/lint/py2.yml

@@ -27,7 +27,6 @@ py2:
         - testing/mochitest
         - testing/mozharness
         - testing/raptor
-        - testing/runtimes
         - testing/tools
         - testing/tps
         - testing/web-platform