I'm posting this as a reference to others who have had the same problem.
$ rake
rake aborted!
No Rakefile found (looking for: rakefile, Rakefile, rakefile.rb, Rakefile.rb)
/home/travis/.rvm/gems/ruby-1.9.3-p551/bin/ruby_executable_hooks:15:in `eval'
/home/travis/.rvm/gems/ruby-1.9.3-p551/bin/ruby_executable_hooks:15:in `<main>'
(See full trace by running task with --trace)
The command "rake" exited with 1.
The above is output when building a Node.JS project on Travis-CI. The .travis.yml file is valid:
language: node_js
node_js:
- "0.12"