Merge branch '2.0.x' into 1.0.x

Author: allflame

src/Context/Extractor/EnvContextExtractor.php

@@ -6,8 +6,9 @@
 use Jaeger\Codec\CodecRegistry;
 use Jaeger\Span\Context\SpanContext;
 use Symfony\Component\Console\ConsoleEvents;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
-class EnvContextExtractor implements ContextExtractorInterface
+class EnvContextExtractor implements ContextExtractorInterface, EventSubscriberInterface
 {
     /**
      * @var CodecInterface[]

src/Context/Extractor/HeaderContextExtractor.php

@@ -4,11 +4,12 @@
 use Jaeger\Codec\CodecInterface;
 use Jaeger\Codec\CodecRegistry;
 use Jaeger\Span\Context\SpanContext;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpKernel\Event\GetResponseEvent;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
 use Symfony\Component\HttpKernel\KernelEvents;
 
-class HeaderContextExtractor implements ContextExtractorInterface
+class HeaderContextExtractor implements ContextExtractorInterface, EventSubscriberInterface
 {
     /**
      * @var CodecInterface[]