add span description

Author: alekitto

src/Tracing/HttpClient/AbstractTraceableHttpClient.php

@@ -52,6 +52,7 @@ public function request(string $method, string $url, array $options = []): Respo
 
             $context = new SpanContext();
             $context->setOp('http.client');
+            $context->setDescription('HTTP ' . $method);
             $context->setTags([
                 'http.method' => $method,
                 'http.url' => $url,

tests/Tracing/HttpClient/TraceableHttpClientTest.php

@@ -77,6 +77,7 @@ public function testRequest(): void
         $this->assertCount(2, $spans);
         $this->assertNull($spans[1]->getEndTimestamp());
         $this->assertSame('http.client', $spans[1]->getOp());
+        $this->assertSame('HTTP POST', $spans[1]->getDescription());
         $this->assertSame([
             'http.method' => 'POST',
             'http.url' => 'http://www.example.org/test-page',
@@ -88,6 +89,7 @@ public function testRequest(): void
         $this->assertCount(2, $spans);
         $this->assertNotNull($spans[1]->getEndTimestamp());
         $this->assertSame('http.client', $spans[1]->getOp());
+        $this->assertSame('HTTP POST', $spans[1]->getDescription());
         $this->assertSame([
             'http.method' => 'POST',
             'http.url' => 'http://www.example.org/test-page',