pid checks in running? should verify that the process is indeed alive

[petejkim]

The following fails after a restart because pid isn't cleaned up correctly on box shut down.

https://github.com/nitrous-io/autoparts/blob/master/lib/autoparts/packages/apache2.rb#L85

      def running?
        pid = Path.var + name + "run" + "httpd.pid"
        pid.exist?
      end

Do something like this instead:

https://github.com/nitrous-io/autoparts/blob/master/lib/autoparts/packages/mongodb.rb#L84

      def running?
        if mongod_pid_file_path.exist?
          pid = File.read(mongod_pid_file_path).strip
          if pid.length > 0 && `ps -o cmd= #{pid}`.include?(mongod_path.basename.to_s)
            return true
          end
        end
        false
      end