Ruby on Rails

Hi there - I'm a ruby newbie and am stuck on the Getting Started with Rails app.  See output below.  Problem arose when I ran the rake db:migrate command.  I also tried the 'rake db:migrate RAILS_ENV=development' command which may be obvious.  Any ideas on how to fix this?  

Many thanks!!

$ ruby -v

ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-darwin10.8.0]

$ rails -v

Rails 4.0.0

$ rails s

=> Booting WEBrick

=> Rails 4.0.0 application starting in development on http://0.0.0.0:3000

=> Run `rails server -h` for more startup options

=> Ctrl-C to shutdown server

[2013-10-28 20:55:15] INFO  WEBrick 1.3.1

[2013-10-28 20:55:15] INFO  ruby 1.9.3 (2013-02-22) [x86_64-darwin10.8.0]

[2013-10-28 20:55:15] INFO  WEBrick::HTTPServer#start: pid=654 port=3000

Started GET "/" for 127.0.0.1 at 2013-10-28 20:55:37 -0700

  ActiveRecord::SchemaMigration Load (0.1ms)  SELECT "schema_migrations".* FROM "schema_migrations"

ActiveRecord::PendingMigrationError (Migrations are pending; run 'rake db:migrate RAILS_ENV=development' to resolve this issue.):

  activerecord (4.0.0) lib/active_record/migration.rb:379:in `check_pending!'

  activerecord (4.0.0) lib/active_record/migration.rb:366:in `call'

  actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'

  activesupport (4.0.0) lib/active_support/callbacks.rb:373:in `_run__518996502029972034__call__callbacks'

  activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'

  actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'

  actionpack (4.0.0) lib/action_dispatch/middleware/reloader.rb:64:in `call'

  actionpack (4.0.0) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'

  actionpack (4.0.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'

  actionpack (4.0.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'

  railties (4.0.0) lib/rails/rack/logger.rb:38:in `call_app'

  railties (4.0.0) lib/rails/rack/logger.rb:21:in `block in call'

  activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `block in tagged'

  activesupport (4.0.0) lib/active_support/tagged_logging.rb:25:in `tagged'

  activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `tagged'

  railties (4.0.0) lib/rails/rack/logger.rb:21:in `call'

  actionpack (4.0.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'

  rack (1.5.2) lib/rack/methodoverride.rb:21:in `call'

  rack (1.5.2) lib/rack/runtime.rb:17:in `call'

  activesupport (4.0.0) lib/active_support/cache/strategy/local_cache.rb:83:in `call'

  rack (1.5.2) lib/rack/lock.rb:17:in `call'

  actionpack (4.0.0) lib/action_dispatch/middleware/static.rb:64:in `call'

  railties (4.0.0) lib/rails/engine.rb:511:in `call'

  railties (4.0.0) lib/rails/application.rb:97:in `call'

  rack (1.5.2) lib/rack/lock.rb:17:in `call'

  rack (1.5.2) lib/rack/content_length.rb:14:in `call'

  rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'

  /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'

  /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'

  /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'

  Rendered /usr/local/rvm/gems/ruby-1.9.3-p392/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/_source.erb (0.8ms)

  Rendered /usr/local/rvm/gems/ruby-1.9.3-p392/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/_trace.erb (1.1ms)

  Rendered /usr/local/rvm/gems/ruby-1.9.3-p392/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (0.9ms)

  Rendered /usr/local/rvm/gems/ruby-1.9.3-p392/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (22.4ms)

[2013-10-28 20:55:38] WARN  Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true