Link to Yosemite marketing page
Only change to zsh if it is not the shell

`chsh` requires a password input, which we want to avoid where possible.
Don't use /etc/zshrc

* Using zshrc causes path_helper to override PATH from zshenv
* We set up rbenv among other things in zshenv

https://github.com/thoughtbot/dotfiles/pull/307
Changes heroku-config plugin url to use https

Many corporate firewalls block the git:// protocol.
Changing this URI to use https:// makes it usable for more people.
The other Git URIs are all using https://.
This was previously the only exception.
Make rbenv idempotent, install Ruby 2.1.4

* Don't repeat ourselves by using variables.
* Use more consistent variable naming and use of `local` in functions.
* Use `snake_case` for variable names and `ALLCAPS` for environment variables.
  https://github.com/thoughtbot/guides/tree/master/style#shell
* Use Bash double-bracket.
* Set current shell to newest Ruby version.
* Don't install `--pre` version of Bundler.

https://www.ruby-lang.org/en/news/2014/10/27/ruby-2-1-4-released/
Fix typo

https://github.com/thoughtbot/laptop/issues/319
Add $HOME/.rbenv to $PATH even if it's installed
Remove rbenv-gem-rehash plugin installation

This plugin was merged into rbenv
https://github.com/sstephenson/rbenv/pull/638
Remove redundant Foreman

It is installed earlier via https://toolbelt.heroku.com/
Remove Heroku Config

I haven't been using `heroku config:pull`, etc. for some time.
Instead, I've been using more targeted shell lines insides our
[`bin/setup`] convention, such as:

    if ! grep -F "FILEPICKER" .env > /dev/null; then
      heroku config --remote staging | grep "FILEPICKER" >> .env
      sed -i '' 's/\:/=/' .env
      sed -i '' 's/ //g' .env
    fi

[`bin/setup`]: http://robots.thoughtbot.com/bin-setup

This is more targeted and automated than using `heroku config:pull`.
Merge remote-tracking branch 'upstream/master'
updating to latest upstream laptop and adding additional local brews and casks