feat(test): remove IE from saucelabs test.
feat(test): remove IE from saucelabs test.

IE10+ is supported, but wonnt be tested in ci.
The tests passes perfectly when ran on local IE10.

leancloud/js-realtime-sdk,leeyeh/js-realtime-sdk,leeyeh/js-realtime-sdk,leancloud/js-realtime-sdk,leeyeh/js-realtime-sdk