Merge branch 'fix/#226-improve-sapi-stream-emitter-tests-and-string-cast'

Close #226

Author: Ocramius

src/Response/SapiStreamEmitter.php

@@ -64,6 +64,7 @@ private function emitBody(ResponseInterface $response, $maxBufferLength)
 
         if (! $body->isReadable()) {
             echo $body;
+            return;
         }
 
         while (! $body->eof()) {
@@ -94,6 +95,7 @@ private function emitBodyRange(array $range, ResponseInterface $response, $maxBu
 
         if (! $body->isReadable()) {
             echo substr($body->getContents(), $first, $length);
+            return;
         }
 
         $remaining = $length;