Remove hard coded Sauce authentication

This prevents forks to have their own Sauce accounts. The authentication
information should come from the Travis account configuration, not from
what's in the repository.

.travis.yml

@@ -13,9 +13,4 @@ env:
   - TEST_BROWSER_NAME=safari TEST_BROWSER_OS='OS X 10.11'
 before_script: npm install -g karma-cli
 addons:
-  sauce_connect:
-    username:
-      secure: "Y5+WRK1ThvctFQNchjW2jly9eLrxe9k8wkKZhS2OGT3SDAmFZnJADswbk/jEbhtl+ZclXybz0uy8Y5YT1PzVCySOqwvy5viIvMZ1xXlOMt1wwJIYbsb3AbOTt3lS+GBXB7RSk0Um5nVx+IMDDIjfS+kQ53NeR1+a/RrDaVNfDEE="
-  jwt:
-    secure: "MHYV2PhoZtNdeSNgRQjLRSn8T9BmwvwBNTgzwOfrUrwU4kVH16ETWOCnygybuRtYC/LNwQxe5W0hcb4rqOzlOO+fWr7OUdRAg8MPXVK0v3WVRu0BpgDIqMXlAbSp2IyCADjqNxG4pmGyrlfAhJ5yO7moaHpjU4QkkXX6QrvjmH4="
-
+  sauce_connect: true