Rakefile in citeproc-ruby-1.1.2 vs Rakefile in citeproc-ruby-1.1.3

@@ -37,12 +37,16 @@
 require 'cucumber/rake/task'
 Cucumber::Rake::Task.new(:cucumber) do |t|
   t.profile = 'default'
 end
 
-require 'coveralls/rake/task'
-Coveralls::RakeTask.new
-task :test_with_coveralls => [:spec, :cucumber, 'coveralls:push']
+begin
+  require 'coveralls/rake/task'
+  Coveralls::RakeTask.new
+  task :test_with_coveralls => [:spec, :cucumber, 'coveralls:push']
+rescue LoadError => e
+  # ignore
+end
 
 task :release do |t|
   system "gem build citeproc-ruby.gemspec"
   system "git tag #{CiteProc::Ruby::VERSION}"
   system "git push --tags"