bumped Gemfile

added rack-handlers and http servers (thin, unicorn) for testing

finer control of pry and pry-byebug versions
smarter production setup scripts

check-system.sh - checks that "ruby" (on a server's PATH) meets the
required ruby version as captured by openbel-server.gemspec

install-local-ruby.sh - uses ruby-build to install the ruby captured by
.ruby-version, installs to vendor/ruby-$(cat .ruby-version).  also
installs the latest bundler.

install.sh - orchestrates the above scripts and installs all gems with
bundle install, installs offline in deployment mode and pushs binstubs
to bin/ and gems to vendor/bundle..reads gems from vendor/cache

refs #5