Dropped support for PHP 7.0

.travis.yml

@@ -3,7 +3,6 @@ language: php
 sudo: false
 
 php:
-  - 7.0
   - 7.1
   - 7.2
 

composer.json

@@ -9,7 +9,7 @@
     ],
     "minimum-stability": "stable",
     "require": {
-        "php": ">=7.0",
+        "php": ">=7.1",
         "psr/http-message": "^1.0"
     },
     "require-dev": {

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "content-hash": "4a0ecca27d108ff51eafc6a5a5cd17fe",
+    "content-hash": "af39391ec89831e5552cd0018816e53e",
     "packages": [
         {
             "name": "psr/http-message",
@@ -1570,7 +1570,7 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": ">=7.0"
+        "php": ">=7.1"
     },
     "platform-dev": []
 }