Next generation of iOS Template

[chrisballinger]

Instead of using a bash script AND cookiecutter, maybe we could simplify things a bit so it's not such a pain to work on the template:

• https://github.com/yonaskolb/XcodeGen - generates Xcode projects from a YAML template
• https://help.github.com/en/github/creating-cloning-and-archiving-repositories/creating-a-template-repository - native github template repos instead of cookiecutter