Make sure Curl uses TLS >= v1.2. Fixes #53.

Author: Andrew Coates

src/Message/AbstractRequest.php

@@ -126,6 +126,13 @@ public function getHttpMethod()
 
     public function sendData($data)
     {
+        // Stripe only accepts TLS >= v1.2, so make sure Curl is told
+        $config = $this->httpClient->getConfig();
+        $curlOptions = $config->get('curl.options');
+        $curlOptions[CURLOPT_SSLVERSION] = 6;
+        $config->set('curl.options', $curlOptions);
+        $this->httpClient->setConfig($config);
+        
         // don't throw exceptions for 4xx errors
         $this->httpClient->getEventDispatcher()->addListener(
             'request.error',