Added backtraces to HTTP calls.

Fixes #16

tests/Record/HttpTest.php

@@ -2,6 +2,7 @@
 
 namespace Rarst\Laps\Tests\Record;
 
+use Brain\Monkey\Functions;
 use Rarst\Laps\Record\Http_Record_Collector;
 use Rarst\Laps\Tests\LapsTestCase;
 use Symfony\Component\Stopwatch\Stopwatch;
@@ -10,6 +11,9 @@ class HttpTest extends LapsTestCase {
 
 	public function testCollector() {
 
+		Functions\expect( 'wp_normalize_path' )->zeroOrMoreTimes()->andReturnFirstArg();
+		Functions\expect( 'wp_debug_backtrace_summary' )->zeroOrMoreTimes()->andReturn( [] );
+
 		$stopwatch = new Stopwatch();
 		$url       = 'https://example.com/';
 		$collector = new Http_Record_Collector( $stopwatch );