If the tests fail, return a non-zero exit code

Author: GeoffreyBooth

Cakefile

@@ -407,12 +407,14 @@ runTests = (CoffeeScript) ->
 
 
 task 'test', 'run the CoffeeScript language test suite', ->
-  runTests CoffeeScript
+  testResults = runTests CoffeeScript
+  process.exit 1 unless testResults
 
 
 task 'test:browser', 'run the test suite against the merged browser script', ->
   source = fs.readFileSync "docs/v#{majorVersion}/browser-compiler/coffee-script.js", 'utf-8'
   result = {}
   global.testingBrowser = yes
   (-> eval source).call result
-  runTests result.CoffeeScript
+  testResults = runTests result.CoffeeScript
+  process.exit 1 unless testResults