Fix travis build

Author: shulard

.travis.yml

@@ -31,6 +31,8 @@ before_install:
 install:
   - travis_retry composer update ${COMPOSER_FLAGS} --prefer-source --no-interaction
 
+before_script: vendor/bin/http_test_server > /dev/null 2>&1 &
+
 script:
   - $TEST_COMMAND