Remove the allow_failures configuration for PHP 7 in .travis.yml.

PHP 7 is now released and so we should officially support it.

Author: tomzx

.travis.yml

@@ -7,10 +7,6 @@ php:
     - 7.0
     - hhvm
 
-matrix:
-    allow_failures:
-        - php: 7.0
-
 sudo: false
 
 before_script:
@@ -23,4 +19,4 @@ script:
 after_script:
     - wget https://scrutinizer-ci.com/ocular.phar
     - php ocular.phar code-coverage:upload --format=php-clover log/coverage.xml
-    - php bin/php-semver-checker-git suggest --allow-detached --details -vvv --include-before=src --include-after=src
+    - php bin/php-semver-checker-git suggest --allow-detached -vvv --details --include-before=src --include-after=src