update README for ie 6, 7

Author: nidhimj22

README.md

@@ -18,5 +18,11 @@ One test is failing on purpose as a demo of BrowserStack catching bugs in differ
 ###Sample test
  - To run: `karma start`
 
+###Note
+ - IE 6 and 7 Tests on Karma version 0.13 may fail(output - browser not captured).
+ - Use Karmav0.12 or below and add `transports: ['websocket','jsonp-polling']` to the karma.conf.js file
+ - Checkout [karma issue] for more details.
+
 [here]:https://github.com/browserstack/karma-browserstack-launcher
 [dashboard]:https://www.browserstack.com/automate
+[karma issue]:https://github.com/karma-runner/karma/issues/983