`rake test` errors on thoughtbot/paperclip

gistfile1.txt

 1) Error:
test: A multipage PDF being thumbnailed at 100x100 with cropping should create the thumbnail when sent #make. (ThumbnailTest):
Paperclip::NotIdentifiedByImageMagickError: /Users/etagwerker/Projects/paperclip/test/fixtures/twopage.pdf is not recognized by the 'identify' command.
    /Users/etagwerker/Projects/paperclip/lib/paperclip/geometry.rb:29:in `from_file'
    /Users/etagwerker/Projects/paperclip/lib/paperclip/thumbnail.rb:35:in `initialize'
    /Users/etagwerker/Projects/paperclip/test/thumbnail_test.rb:290:in `new'
    /Users/etagwerker/Projects/paperclip/test/thumbnail_test.rb:290:in `block (3 levels) in <class:ThumbnailTest>'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:400:in `call'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:400:in `block in run_current_setup_blocks'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:399:in `each'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:399:in `run_current_setup_blocks'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:381:in `block in create_test_from_should_hash'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/mocha-0.10.0/lib/mocha/integration/mini_test/version_142_to_172.rb:27:in `run'

  2) Error:
test: A multipage PDF being thumbnailed at 100x100 with cropping should report its correct current and target geometries. (ThumbnailTest):
Paperclip::NotIdentifiedByImageMagickError: /Users/etagwerker/Projects/paperclip/test/fixtures/twopage.pdf is not recognized by the 'identify' command.
    /Users/etagwerker/Projects/paperclip/lib/paperclip/geometry.rb:29:in `from_file'
    /Users/etagwerker/Projects/paperclip/lib/paperclip/thumbnail.rb:35:in `initialize'
    /Users/etagwerker/Projects/paperclip/test/thumbnail_test.rb:290:in `new'
    /Users/etagwerker/Projects/paperclip/test/thumbnail_test.rb:290:in `block (3 levels) in <class:ThumbnailTest>'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:400:in `call'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:400:in `block in run_current_setup_blocks'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:399:in `each'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:399:in `run_current_setup_blocks'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:381:in `block in create_test_from_should_hash'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/mocha-0.10.0/lib/mocha/integration/mini_test/version_142_to_172.rb:27:in `run'

  3) Error:
test: A multipage PDF being thumbnailed at 100x100 with cropping should report its correct format. (ThumbnailTest):
Paperclip::NotIdentifiedByImageMagickError: /Users/etagwerker/Projects/paperclip/test/fixtures/twopage.pdf is not recognized by the 'identify' command.
    /Users/etagwerker/Projects/paperclip/lib/paperclip/geometry.rb:29:in `from_file'
    /Users/etagwerker/Projects/paperclip/lib/paperclip/thumbnail.rb:35:in `initialize'
    /Users/etagwerker/Projects/paperclip/test/thumbnail_test.rb:290:in `new'
    /Users/etagwerker/Projects/paperclip/test/thumbnail_test.rb:290:in `block (3 levels) in <class:ThumbnailTest>'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:400:in `call'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:400:in `block in run_current_setup_blocks'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:399:in `each'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:399:in `run_current_setup_blocks'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/shoulda-2.11.3/lib/shoulda/context.rb:381:in `block in create_test_from_should_hash'
    /Users/etagwerker/.rvm/gems/ruby-1.9.2-p290@paperclip/gems/mocha-0.10.0/lib/mocha/integration/mini_test/version_142_to_172.rb:27:in `run'

  4) Failure:
test: A multipage PDF should start with two pages with dimensions 612x792. (ThumbnailTest) [/Users/etagwerker/Projects/paperclip/test/thumbnail_test.rb:285]:
<"612x792612x792"> expected but was
<"">.

552 tests, 982 assertions, 1 failures, 3 errors, 0 skips

Test run options: --seed 33332
rake aborted!
Command failed with status (1): [/Users/etagwerker/.rvm/rubies/ruby-1.9.2-p...]

Tasks: TOP => test
(See full trace by running task with --trace)