Add note about not requiring a profile if creds are in the environment

@@ -40,6 +40,9 @@ Where ``command`` is one of:
 The ``config file`` is a YAML format file containing all of the information
 The ``config file`` is a YAML format file containing all of the information
 about your Lambda function.
 about your Lambda function.
 
 
+If you use environment variables for your AWS credentials (as normally supported by boto),
+simply exclude the ``profile`` element from the YAML file.
+
 An example project based on a Kinesis stream can be found in
 An example project based on a Kinesis stream can be found in
 [samples/kinesis](https://github.com/garnaat/kappa/tree/develop/samples/kinesis).
 [samples/kinesis](https://github.com/garnaat/kappa/tree/develop/samples/kinesis).
 
 
@@ -56,4 +59,4 @@ The basic workflow is:
 * Run ``kappa --config <path-to-config> tail`` to see more output
 * Run ``kappa --config <path-to-config> tail`` to see more output
 
 
 If you have to make changes in your function or in your IAM roles, simply run
 If you have to make changes in your function or in your IAM roles, simply run
-``kappa deploy`` again and the changes will be uploaded as necessary.
\ No newline at end of file
+``kappa deploy`` again and the changes will be uploaded as necessary.