Add jasmine to default rake task

gistfile1.txt

require 'rspec/core'
require 'rspec/core/rake_task'
require 'jasmine-headless-webkit'

# Run Jasmine headless via webkit
Jasmine::Headless::Task.new('jasmine:headless')

# Add to default rake task
if default = Rake.application.instance_variable_get('@tasks')['default']
  default.prerequisites.unshift('jasmine:headless')
end