Upgrading Django

[jpmckinney]

• Django 1.9
  • Drops support for PostGIS 1.5, PostgreSQL 9.0
• Django 1.10
  • Drops support for PostgreSQL 9.1

PostgreSQL >= 9.4 would allow us to drop jsonfield

Also, grep for Django.* \d\. across all projects when upgrading Django for notes on things to update.

[michaelmulley]

Pull request #107 does this upgrade.

I've updated READMEs in represent-canada but have not done so or grepped in other projects.

Re dropping jsonfield, note that the builtin Django JSONField uses Postgres' native JSON datatype, which would involve a data migration and is probably not necessary (while database-level integrity checking is always nice, we don't otherwise care where Postgres can interpret the JSON data or just treats it as a blob of text).

[jpmckinney]

I thought that might be the case. We'll keep jsonfield then.

I've gone through all other repos.