Final Webhook Management API Changes

- Updated Samples
- Additional Functional Tests
- Enabled Travis to do functional tests (with allowed failures) on each build

sample/doc/notifications/SearchWebhookEvents.html

@@ -6,6 +6,7 @@ API used: GET /v1/notifications/webhooks-events</p></div></div></div><div class=
 <p>Creating webhook is sample purposes only. In real scenario, you dont need to create a new webhook everytime you want to search
 for a webhook events. This is made in a sample just to make sure there is minimum of one webhook to listen to.</p></div></div><div class="code"><div class="wrapper"><span class="hljs-comment">/**<span class="hljs-phpdoc"> @var</span> \PayPal\Api\Webhook $webhook */</span>
 <span class="hljs-variable">$webhook</span> = <span class="hljs-keyword">require</span> <span class="hljs-keyword">__DIR__</span> . <span class="hljs-string">'/../bootstrap.php'</span>;
+<span class="hljs-keyword">use</span> <span class="hljs-title">PayPal</span>\<span class="hljs-title">Api</span>\<span class="hljs-title">Authorization</span>;
 
 <span class="hljs-variable">$params</span> = <span class="hljs-keyword">array</span>(</div></div></div><div class="segment"><div class="comments "><div class="wrapper"><p>&#39;start_time&#39;=&gt;&#39;2014-12-06T11:00:00Z&#39;,
 &#39;end_time&#39;=&gt;&#39;2014-12-12T11:00:00Z&#39;</p></div></div><div class="code"><div class="wrapper">);</div></div></div><div class="segment"><div class="comments "><div class="wrapper"><h3 id="search-webhook-events">Search Webhook events</h3></div></div></div><div class="segment"><div class="code"><div class="wrapper"><span class="hljs-keyword">try</span> {
@@ -17,4 +18,5 @@ for a webhook events. This is made in a sample just to make sure there is minimu
 
 ResultPrinter::printResult(<span class="hljs-string">"Search Webhook events"</span>, <span class="hljs-string">"WebhookEventList"</span>, <span class="hljs-keyword">null</span>, <span class="hljs-variable">$params</span>, <span class="hljs-variable">$output</span>);
 
+
 <span class="hljs-keyword">return</span> <span class="hljs-variable">$output</span>;</div></div></div></div></body></html>