Remove references to csv or upload format

This will be determined on upload, the user should be able to upload
either
Protect routes with a decorator

sorts out session availability in templates
with tests
remove irrelevant comment
Do signout and environment stuff

Also comments about things to still be done in upload story
Rename the manifest file

it breaks autocompilation if not, it's harder to make it output to a
different file name and there is enough context in it being in the
manifest directory
Fix tests - we need the fake get context to give and environment
Contact link to mailto for now
Merge pull request #19 from alphagov/template-fixes

Template fixes
Use correct hostname with TLS for GOV.UK
Capitalise Performance Platform as elsewhere

https://github.com/alphagov/government-service-design-manual/commit/4f4e9c534c258f8589230eff7b319d035512efbe

https://github.com/alphagov/government-service-design-manual/pull/220#commitcomment-4250328
Merge pull request #21 from alphagov/template-words-and-urls

Templates: words and URLs
meaningful classes on data set list
Merge pull request #22 from alphagov/template-fixes

meaningful classes on data set list
@tombooth Has verified the code and has authorised this merge.
Set PYTHONUNBUFFERED environment variable

https://docs.python.org/2/using/cmdline.html#envvar-PYTHONUNBUFFERED

Like a lot of things (hi Ruby) Python buffers stdout. This is annoying
in development because it means you might not see the output you're
looking for.

In production-like environments, we should not be putting anything on
stdout that would cause this to be an issue.
Move helpers into their own file

Improve the testing of the requires_authentication decorator. There's
no need to test the decorator in every place that it's used if we
can just test once that it's working.
Add an /upload-data endpoint

The upload endpoint should list the data sets that the user has
access to, and provide a form for each one to allow the user to
upload data.
Make flash messages line up

I don't think .container-fluid should be defined in each of the views.
Upload POST work in progress