Revert "microsoft edge seems not to work"

This reverts commit 5bc6f8a.

Author: calvinmetcalf

.travis.yml

@@ -26,6 +26,8 @@ matrix:
       env: TEST_SUITE=browser BROWSER_NAME=safari BROWSER_VERSION="6..latest"
     - node_js: '4'
       env: TEST_SUITE=browser BROWSER_NAME=android BROWSER_VERSION="4.4..latest"
+    - node_js: '4'
+      env: TEST_SUITE=browser BROWSER_NAME=microsoftedge BROWSER_VERSION="20..latest"
 script: "npm run-script $TEST_SUITE"
 env:
   global: