Fix title of the checked web site

Right now lambda checks for "What Is AWS Lambda?" title on the page. However, the title of the page is "What is AWS Lambda?"

Author: vlad-bezden

doc_source/services-cloudwatchevents-tutorial.md

@@ -33,7 +33,7 @@ This tutorial assumes that you have some knowledge of basic Lambda operations an
    + **Enabled** – True \(checked\)\.
    + **Environment variables**
      + **site** – **https://docs\.aws\.amazon\.com/lambda/latest/dg/welcome\.html**\.
-     + **expected** – **What Is AWS Lambda?**\.
+     + **expected** – **What is AWS Lambda?**\.
 
 1. Choose **Create function**\.
 
@@ -121,4 +121,4 @@ Update the function configuration to cause the function to return an error, whic
 
 1. Choose **Save**\.
 
-Wait a minute, and then check your email for a message from Amazon SNS\.
+Wait a minute, and then check your email for a message from Amazon SNS\.