docs: fix $client->request() HTTP verbs

Author: kenjis

user_guide_src/source/libraries/curlrequest/017.php

@@ -1,3 +1,3 @@
 <?php
 
-$client->setBody($body)->request('put', 'http://example.com');
+$client->setBody($body)->request('PUT', 'http://example.com');

user_guide_src/source/libraries/curlrequest/018.php

@@ -1,3 +1,3 @@
 <?php
 
-$client->request('put', 'http://example.com', ['body' => $body]);
+$client->request('PUT', 'http://example.com', ['body' => $body]);

user_guide_src/source/libraries/curlrequest/019.php

@@ -1,3 +1,3 @@
 <?php
 
-$client->request('get', '/', ['cert' => ['/path/server.pem', 'password']]);
+$client->request('GET', '/', ['cert' => ['/path/server.pem', 'password']]);

user_guide_src/source/libraries/curlrequest/025.php

@@ -1,6 +1,6 @@
 <?php
 
-$client->request('get', '/', [
+$client->request('GET', '/', [
     'headers' => [
         'User-Agent' => 'testing/1.0',
         'Accept'     => 'application/json',