Add some documentation on handling SSL errors

Author: colinodell

TROUBLESHOOTING.md

@@ -3,6 +3,7 @@ If you can't find a solution below, please open an [issue](https://github.com/se
 ## Table of Contents
 
 * [Viewing the Request Body](#request-body)
+* [Handling SSL Errors](#ssl-errors)
 
 <a name="request-body"></a>
 ## Viewing the Request Body
@@ -14,3 +15,10 @@ echo $response->statusCode();
 echo $response->body();
 echo $response->headers();
 ```
+
+<a name="ssl-errors">
+## Handling SSL Errors
+
+If any SSL errors occur during API calls, a `RuntimeException` will be thrown. This will provide information to help debug the issue further.
+
+If the issue is caused by an unrecognized certificate, it may be possible that PHP is unable to locate your system's CA bundle. An easy fix would be requiring the `composer/ca-bundle` package - this library will automatically detect and use that to locate the CA bundle, or use Mozilla's as a fallback.