Removed Performance Warning, fixed by PR cypress-io#98

Removed Performance Warning, which was fixed by PR cypress-io#98

Author: coryarmbrecht

README.md

@@ -2,9 +2,6 @@
 
 > Saves the code coverage collected during Cypress tests
 
-**⚠️ Performance Warning**
-This plugin will slow down your tests. There will be more web application JavaScript code to execute due to instrumentation, and there will be code coverage information to merge and save after each test. Track issue [#26](https://github.com/cypress-io/code-coverage/issues/26) for current progress.
-
 ## Install
 
 ```shell