chore(build): add Safari8 to CI

Closes angular#3717

Author: marclaval

sauce.conf.js

@@ -125,7 +125,7 @@ var aliases = {
  'SAFARI': ['SL_SAFARI7', 'SL_SAFARI8'],
  'BETA': ['SL_CHROMEBETA', 'SL_FIREFOXBETA'],
  'DEV': ['SL_CHROMEDEV', 'SL_FIREFOXDEV'],
- 'CI': ['SL_CHROME', 'SL_ANDROID5.1']
+ 'CI': ['SL_CHROME', 'SL_ANDROID5.1', 'SL_SAFARI8']
 };
 
 module.exports = {