Update assorted gems

Here is a list produced by bundle update:

- Updating git://github.com/tristanm/jstree-rails.git
- Updating git://github.com/digineo/sunspot.git
- Updating git://github.com/llwt/codemirror-rails.git
- Updating git://github.com/0robustus1/ontology-united.git
- Installing coffee-script-source 1.7.1 (was 1.7.0)
- Installing i18n 0.6.11 (was 0.6.9)
- Installing tzinfo 0.3.40 (was 0.3.39)
- Installing execjs 2.2.1 (was 2.2.0)
- Installing netrc 0.7.7
- Installing diffy 3.0.6 (was 3.0.4)
- Installing ice_cube 0.12.1 (was 0.12.0)
- Installing slop 3.6.0 (was 3.5.0)
- Installing rdf 1.1.4.3 (was 1.1.4)
- Installing redis 3.1.0 (was 3.0.7)
- Installing rspec-core 2.99.1 (was 2.99.0)
- Installing rspec-mocks 2.99.2 (was 2.99.1)
- Installing faker 1.4.2 (was 1.3.0)
- Installing simplecov 0.9.0 (was 0.8.2)
- Installing compass 0.12.7 (was 0.12.6)
- Installing rspec-expectations 2.99.2 (was 2.99.0)
- Installing coffee-script 2.3.0 (was 2.2.0)
- Installing uglifier 2.5.3 (was 2.5.1)
- Installing rubydns 0.8.5 (was 0.8.4)
- Installing rest-client 1.7.2 (was 1.6.7)
- Installing redis-namespace 1.5.1 (was 1.4.1)
- Installing cucumber 1.3.16 (was 1.3.15)
- Installing shoulda-matchers 2.6.2 (was 2.6.1)
- Installing pry-byebug 1.3.3 (was 1.3.2)
- Installing sidekiq 3.2.1 (was 3.1.4)
- Installing capistrano-bundler 1.1.3 (was 1.1.2)
- Installing acts_as_tree 2.0.0 (was 1.6.1)
- Installing sidekiq-failures 0.4.3 (was 0.4.2)
- Installing d3_rails 3.4.10 (was 3.4.8)
- Installing jquery-rails 3.1.1 (was 3.1.0)
- Installing jquery-ui-rails 5.0.0 (was 4.2.1)
- Installing momentjs-rails 2.8.1 (was 2.7.0)
- Installing quiet_assets 1.0.3 (was 1.0.2)
- Installing nokogiri 1.6.3.1 (was 1.6.2.1)
- Installing capybara 2.4.1 (was 2.3.0)

The 'using' lines were removed.


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As sidekiq is part of the update, here is the [Changelog](https://github.com/mperham/sidekiq/blob/master/Changes.md). It seems there was a major bugfix which locks us in to Ruby 2.1. So we should take a closer look at that.