Resolves AI-69:
- uses badges for availability status
- points to new solr index for nutch
- make catalog_searcher_api_endpoint configurable as env var
- updates ruby/rails to 3.1.6/6.1.7.8
- downgrades psych to 3.3.4 (and removes 4.0 work-around)
- fix rubocop issues and rspec tests
- archives old migrations