Drop support for PHP 7.0

.travis.yml

@@ -8,15 +8,13 @@ cache:
 
 matrix:
   include:
-    - php: 7.0
+    - php: 7.1
       env: COMPOSER_ARGUMENTS="--prefer-lowest --prefer-stable"
-    - php: 7.0
     - php: 7.1
     - php: 7.2
     - php: nightly
   allow_failures:
     - php: nightly
-    - php: 7.2
   fast_finish: true
 
 before_script:

composer.json

@@ -12,7 +12,7 @@
         }
     ],
     "require": {
-        "php": ">=7.0",
+        "php": ">=7.1",
         "symfony/polyfill-mbstring": "^1.2"
     },
     "require-dev": {