Merge pull request #31 from PagerDuty/update-migration-guide

Make the migration guide a bit clearer re: Change Events API

docs/pdpyras_migration_guide.html

@@ -102,10 +102,10 @@ <h2>Client Classes<a class="headerlink" href="#client-classes" title="Permalink
 <li><p><code class="docutils literal notranslate"><span class="pre">s/PDSession/ApiClient/g</span></code></p></li>
 </ol>
 <p>The Change Events API client has been merged into the Events API v2 client
-because the differences between these two APIs are trivial enough to support
-them both under the same client class, and there is no method or property name
-overlap between the client classes. Their respective APIs are also documented
-under the same API reference.</p>
+because the former API is effectively a component of the latter. The
+differences are trivial enough to support both use cases with a single client
+class, and there are no method or property name collisions between the two
+original classes.</p>
 </section>
 <section id="exception-classes">
 <h2>Exception Classes<a class="headerlink" href="#exception-classes" title="Permalink to this heading"></a></h2>