boilerplate: Fix for Python 3

Status Job ID Name Coverage
  Build
canceled #18577
build:2.7

canceled #18578
build:3

 
  Test
canceled #18580
allowed to fail
lint:2.7

canceled #18584
allowed to fail
lint:3

canceled #18579
pyflakes:2.7

canceled #18583
pyflakes:3

canceled #18581
unittests:2.7

canceled #18585
unittests:3

canceled #18582
allowed to fail
unittests-modules:2.7

canceled #18586
allowed to fail
unittests-modules:3

 
  Deploy
canceled #18587
doc:2.7

canceled #18588
doc:3