API Versions

The README.md specifies that the IntercomClient can be configured to use any API version by providing the 3rd argument to the constructor. However, the constructor only takes 2 arguments.

It seems that the correct way to configure the version would be to instantiate the client like so

$client = new IntercomClient('token', ['headers' => ['Intercom-Version' => '1.1']]);

Users

The README.md specifies that if an API version between 1.0 and 1.4 is used then one can work with users by accessing the users property on the IntercomClient class, e.g. $client->users->create(...). However, the users property doesn't exist.

Leads

The README.md specifies that if an API version between 1.0 and 1.4 is used then one can work with leads accessing the leads property. However, the leads property doesn't exist

Counts

The README.md specifies that counts can be accessed on the client, but the property doesn't exist

We generally like to keep up to date with our dependencies, but it looks like with version 5 you no longer support API version < 2.0, which given the age of API version 1.4 is understandable. However, it would be nice if the README reflected this fact and/or if the release notes for version 5 had reflected the fact.