Http adapter curl missing delete method

Fix static tests & use strict comparison

Author: ihor-sviziev

lib/internal/Magento/Framework/HTTP/Adapter/Curl.php

@@ -166,22 +166,21 @@ public function write($method, $url, $http_ver = '1.1', $headers = [], $body = '
         // set url to post to
         curl_setopt($this->_getResource(), CURLOPT_URL, $url);
         curl_setopt($this->_getResource(), CURLOPT_RETURNTRANSFER, true);
-        if ($method == \Zend_Http_Client::POST) {
+        if ($method === \Zend_Http_Client::POST) {
             curl_setopt($this->_getResource(), CURLOPT_POST, true);
             curl_setopt($this->_getResource(), CURLOPT_CUSTOMREQUEST, 'POST');
             curl_setopt($this->_getResource(), CURLOPT_POSTFIELDS, $body);
-        } elseif ($method == \Zend_Http_Client::PUT) {
+        } elseif ($method === \Zend_Http_Client::PUT) {
             curl_setopt($this->_getResource(), CURLOPT_CUSTOMREQUEST, 'PUT');
             curl_setopt($this->_getResource(), CURLOPT_POSTFIELDS, $body);
-        } elseif ($method == \Zend_Http_Client::GET) {
+        } elseif ($method === \Zend_Http_Client::GET) {
             curl_setopt($this->_getResource(), CURLOPT_HTTPGET, true);
             curl_setopt($this->_getResource(), CURLOPT_CUSTOMREQUEST, 'GET');
-        } elseif ($method == \Zend_Http_Client::DELETE) {
+        } elseif ($method === \Zend_Http_Client::DELETE) {
             curl_setopt($this->_getResource(), CURLOPT_CUSTOMREQUEST, 'DELETE');
             curl_setopt($this->_getResource(), CURLOPT_POSTFIELDS, $body);
         }
 
-
         if ($http_ver === \Zend_Http_Client::HTTP_1) {
             curl_setopt($this->_getResource(), CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
         } elseif ($http_ver === \Zend_Http_Client::HTTP_0) {