[DRE-maint] Bug#830060: Could not find 'appraisal'

[Andreas Beckmann]

Followup-For: Bug #830060

Similar problems in jessie:

ruby -e 'gem "appraisal"'
/usr/lib/ruby/2.1.0/rubygems/dependency.rb:298:in `to_specs': Could not find 'appraisal' (>= 0) among 18 total gem(s) (Gem::LoadError)
        from /usr/lib/ruby/2.1.0/rubygems/dependency.rb:309:in `to_spec'
        from /usr/lib/ruby/2.1.0/rubygems/core_ext/kernel_gem.rb:53:in `gem'
        from -e:1:in `<main>'

Andreas