travis: removed PHP 7.1 from allowed failures

Author: dg

.travis.yml

@@ -15,9 +15,6 @@ matrix:
         - php: 7.0
           env: coverage="--coverage ./coverage.xml --coverage-src ./src" PHP_BIN=phpdbg
 
-    allow_failures:
-        - php: 7.1
-
 script:
     - vendor/bin/tester -p $PHP_BIN tests -s $coverage
     - php temp/code-checker/src/code-checker.php --short-arrays