Update docs to indicate you can use cognito pool authoriser and claims with lambda-proxy

docs/providers/aws/events/apigateway.md

@@ -265,7 +265,12 @@ functions:
             arn: arn:aws:cognito-idp:us-east-1:xxx:userpool/us-east-1_ZZZ
 ```
 
-By default the `sub` claim will be exposed in `events.cognitoPoolClaims`, you can add extra claims like so:
+If you are using the default `lambda-proxy` integration, your attributes will be
+exposed at `event.requestContext.authorizer.claims`.
+
+If you want control more control over which attributes are exposed as claims you
+can switch to `integration: lambda` and add the following configuration. The
+claims will be exposed at `events.cognitoPoolClaims`.
 
 ```yml
 functions:
@@ -283,8 +288,6 @@ functions:
               - nickname
 ```
 
-Note: Since claims must be explicitly listed to be exposed, you must use `integration: lambda` integration type to access any claims.
-
 ### Catching Exceptions In Your Lambda Function
 
 In case an exception is thrown in your lambda function AWS will send an error message with `Process exited before completing request`. This will be caught by the regular expression for the 500 HTTP status and the 500 status will be returned.

lib/plugins/aws/package/compile/events/apiGateway/lib/validate.js

@@ -247,7 +247,7 @@ module.exports = {
     if (integration === 'AWS_PROXY'
         && typeof arn === 'string' && arn.match(/^arn:aws:cognito-idp/) && authorizer.claims) {
       const errorMessage = [
-        'Cognito claims can\'t be retrieved when using lambda-proxy as the integration type',
+        'Cognito claims can only be filtered when using the lambda integration type',
       ];
       throw new this.serverless.classes.Error(errorMessage);
     }