* fix unit name: the unit name on Ubuntu is `redis-server.service`
* services which need a working redis require both After= and Wants=
See the description in the `systemd.unit` man page.
The rap scripts might load or run some scripts using relative paths from
the scripts directory, so restore that.
Bundler automatically looks up in parent dirs to find the Gemfile, so
loading gems will work correctly.
Several scripts internally run bundler setup, so no explicit bundler
command is needed. For the others, start up using /usr/bin/bundle
(installed by ruby-bundler) to load the environment.
Now uses Ubuntu's bundler version to install all dependencies at build time
rather than install time. Gems are also now vendored, and no longer pollute the
operating system.