pep8 python module is now in python-pep8 - triggers FTBFS

[Edward Betts <edward@4angle.com>]

The pep8 python module has moved from the pep8 package to python-pep8.

See https://tracker.debian.org/news/752214

/usr/bin/pep8 is still in the pep8 package but now uses python3-pep8

There are 32 packages with a Build-Depends on pep8. These packages usually
make use of pep8 in their test suites. Many of them will need to be updated to
use python-pep8 instead.

Here is the list of packages with a Build-Depends on pep8.

  actdiag aptdaemon autopkgtest
  backup2swift blockdiag botch breadability byobu
  cloud-init custodia
  d-feet dirspec django-sekizai
  fuzzywuzzy
  genbackupdata
  nwdiag
  obnam ovirt-guest-agent
  prospector pygobject python-apt python-cliapp python-flake8 python-netlib python-ttystatus
  seqdiag shortuuid ssh-import-id summain swiftsc syslog-ng
  xcffib

I checked a few of these, in detail:

 - fix for fuzzywuzzy uploaded
 - bug filed for blockdiag
 - fix for django-sekizai pushed to git, e-mailed uploaders

I checked python-ttystatus and obnam. I found they use /usr/bin/pep8 instead of
importing the pep8 module, so they don't need updating.

More examples of pep8 use here:

    https://codesearch.debian.net/results/import%20pep8

-- 
Edward.