Configure vim

* Update provisioning to set up vim.
* Add option to skip update of git repos.
Replace ansible playbook with roles

* Replace the ansible playbook system.yml with the ansible role system.
* Move all provisioning files to the directory provisioning.
Set up SSH keys for the vagrant user
Populate .gitconfig with user name and email

Make ansible populate a basic .gitconfig for the user using a template.
Don't use sudo for user files

Make sure ansible doesn't use sudo for creating user files.