Revert "Don't appbundle from within bundle exec"

[lamont-granquist]

So the problems with this are very annoying:

1. Things like travis will set BUNDLE_GEMFILE but the user may not bundle install or bundle exec so we can't rely on that as a test to see if we're in bundler.

2. We rely on eval "$(/opt/chefdk/bin/chef shell-init bash)" to clean up the rvm environment in travis.

• GEM_PATH + GEM_HOME are set by rvm and must be cleaned in order to run the shell-init command
• after shell-init is run GEM_PATH + GEM_HOME are set pointing at chefdk + the .chefdk dir

The workflow that we would have to support is:

• use rvm and create an empty gemset
• eval "$(/opt/chefdk/bin/chef shell-init bash)" and reset the env vars <-- this relies on the binstubs to reset the env to even invoke the chef command.
• /opt/chefdk/embedded/bin/chef --version should work

Note that what people do is call embedded directly, that's not a typo there, so it bypasses the binstubs and just uses chefdk as a normal ruby.