Update dependencies to 2018 versions
When working on #14 (closed), a deployment attempt gave the following friendly warnings:
: 2leinen@macsl[zrcal]; gcloud app deploy
WARNING: lxml version "2.3.5" is deprecated, use one of: "3.7.3"
WARNING: setuptools version "0.6c11" is deprecated, use one of: "36.6.0"
WARNING: django version "1.5" is deprecated, use one of: "1.4", "1.11"
Services to deploy:
descriptor: [/Users/leinen/projects/zrcal/app.yaml]
source: [/Users/leinen/projects/zrcal]
target project: [zrcal-1161]
target service: [default]
target version: [20181228t183237]
target url: [https://zrcal-1161.appspot.com]
Do you want to continue (Y/n)? y
We should try to upgrade to the supported newer versions of those prerequisites.