Restore "test" as the default rake task

.travis.yml

@@ -1,6 +1,5 @@
 language: ruby
 before_install: sudo pip install docutils
-script: bundle exec rake test
 rvm:
   - 1.9.3
   - 2.0.0
@@ -9,4 +8,4 @@ rvm:
 jdk:
   - oraclejdk8
 notifications:
-  email: false
+  email: false

CONTRIBUTING.md

@@ -53,12 +53,12 @@ Finally add your [tests](#testing).
 
 To run the tests:
 
-    $ rake test
+    $ rake
 
 When adding support for a new markup library, create a `README.extension` in `test/markups` along with a `README.extension.html`. As you may imagine, the `README.extension` should be your known input and the
 `README.extension.html` should be the desired output.
 
-Now run the tests: `rake test`
+Now run the tests: `rake`
 
 If nothing complains, congratulations!
 

Rakefile

@@ -1,5 +1,7 @@
 #!/usr/bin/env rake
 
+require "bundler/gem_tasks"
+
 require 'rake/testtask'
 Rake::TestTask.new(:test) do |test|
   test.libs << 'lib' << 'test'
@@ -12,4 +14,4 @@ task :console do
   sh "irb -I lib -r bundler/setup -r github/markup"
 end
 
-task :default
+task :default => :test