Replace HTTPSConnection in NEC plugin

Replace HTTPSConnection in NEC plugin PFC driver with Requests.

SSL Verification is from now on enabled by default.

This changes the default behaviour and is the primary intention of this
change: verify SSL certificates.

This might break existing configuration/setups where the SSL certificate
used by the NEC PFC driver would not pass the verification.

SecurityImpact
DocImpact
Partial-Bug: 1188189

Change-Id: I1e5fdc9c2ed5b812aa6509d1639bd499acc5c337
Fix Jenkins translation jobs

The job neutron-propose-translation-update
does not update from
transifex since our po files contain duplicate entries where
obsolete entries duplicate normal entries.

Remove all obsolete entries to fix the job.

Add test to pep8 that checks that no new breakages get
introduced.

Change-Id: I9c680eeefecfa124c5b2900b7fa7a0a8f7e8ebd6
Closes-Bug: #1299349
Merge "Replace HTTPSConnection in NEC plugin"
Merge "Fix Jenkins translation jobs"