Merge pull request #411 from jennifer-shehane/patch-2

Fix typo Whenver -> Whenever

Author: basarat

docs/testing/cypress.md

@@ -166,7 +166,7 @@ page.username.type('john');
 ```
 
 ## Tip: Implicit assertion 
-Whenver a cypress command fails you get a nice error (instead of something like `null` with many other frameworks) so you fail quickly and know exactly when a test fails e.g. 
+Whenever a cypress command fails you get a nice error (instead of something like `null` with many other frameworks) so you fail quickly and know exactly when a test fails e.g. 
 
 ```
 cy.get('#foo')