Fix Duplicate web-console entries in Gemfile

I got following error when invoking bundle install after creating new edge rails app using 'ruby edge_rails new --dev'.

  You cannot specify the same gem twice with different version requirements.
  You specified: web-console (>= 0) and web-console (~> 2.0)

So I removed duplicate entry of web-console in Gemfile.
I'm not sure if we should wait until next release of web-console which allows rails 5.0 is released, though.

Please let me know if I've misunderstood.

Thanks!