Set flake8 flag in setup.cfg.
Handbook: Talk about post type-specific CSS class names.
Add some detail to a couple of location related comments in conf.py.
Also update Travis CI config.
Merge pull request #1002 from ramiro/location-notes-in-conf.py

Add some detail to a couple of location related comments in conf.py.
Merge pull request #1001 from ramiro/clarify-classes-are-CSS

Handbook: Talk about post type-specific CSS class names.
Merge pull request #999 from ramiro/flake8-config

Set flake8 flag in setup.cfg.
Fix #1004
Merge pull request #1005 from getnikola/hide-sourcelink-is-backwards

Fix #1004
merge