title: Logstash Plugin not getting installed
body: <p>I am trying to install the <strong>kafka output plugin for logstash 1.5.0.beta1</strong>.<br>
  I had done it previously using the command  </p>
  
  <pre><code>$LS_HOME/bin/plugin install logstash-output-kafka 
  </code></pre>
  
  <p>as given on the logstash website.</p>
  
  <p>But now the installation is giving me the following error:            </p>
  
  <pre><code>Clamp::UsageError: No such sub-command 'logstash-output-kafka'
       signal_usage_error at /home/madhura/Softwares/logstash-1.5.0.beta1/vendor/bundle/jruby/1.9/gems/clamp-0.6.3/lib/clamp/command.rb:103
    find_subcommand_class at /home/madhura/Softwares/logstash-1.5.0.beta1/vendor/bundle/jruby/1.9/gems/clamp-0.6.3/lib/clamp/subcommand/execution.rb:28
    instatiate_subcommand at /home/madhura/Softwares/logstash-1.5.0.beta1/vendor/bundle/jruby/1.9/gems/clamp-0.6.3/lib/clamp/subcommand/execution.rb:17
                  execute at /home/madhura/Softwares/logstash-1.5.0.beta1/vendor/bundle/jruby/1.9/gems/clamp-0.6.3/lib/clamp/subcommand/execution.rb:10
                      run at /home/madhura/Softwares/logstash-1.5.0.beta1/lib/logstash/runner.rb:144
                     call at org/jruby/RubyProc.java:271
                      run at /home/madhura/Softwares/logstash-1.5.0.beta1/lib/logstash/runner.rb:171
                     call at org/jruby/RubyProc.java:271
               initialize at /home/madhura/Softwares/logstash-1.5.0.beta1/vendor/bundle/jruby/1.9/gems/stud-0.0.18/lib/stud/task.rb:12
  </code></pre>
  
  <p>Kindly help me find the reason and install the plugin</p>