Drop PHP 7.1

This is according to our formal, published, policy to only support
eol PHP after 6 months.

See https://phpspreadsheet.readthedocs.io/en/latest/#php-version-support

.travis.yml

@@ -2,7 +2,6 @@ language: php
 dist: bionic
 
 php:
-  - 7.1
   - 7.2
   - 7.3
   - 7.4

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com)
 and this project adheres to [Semantic Versioning](https://semver.org).
 
+## [Unreleased]
+
+### Changed
+
+- Drop support for PHP 7.1, according to https://phpspreadsheet.readthedocs.io/en/latest/#php-version-support
+
 ## [1.12.0] - 2020-04-27
 
 ### Added

composer.json

@@ -35,11 +35,11 @@
             "php-cs-fixer fix --ansi"
         ],
         "versions": [
-            "phpcs --report-width=200 samples/ src/ tests/ --ignore=samples/Header.php --standard=PHPCompatibility --runtime-set testVersion 7.1- -n"
+            "phpcs --report-width=200 samples/ src/ tests/ --ignore=samples/Header.php --standard=PHPCompatibility --runtime-set testVersion 7.2- -n"
         ]
     },
     "require": {
-        "php": "^7.1",
+        "php": "^7.2",
         "ext-ctype": "*",
         "ext-dom": "*",
         "ext-gd": "*",

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "0fd32acfbb0d21f168f495840ffc8d7e",
+    "content-hash": "83ef345a065e12287e792d660b49619b",
     "packages": [
         {
             "name": "markbaker/complex",
@@ -3484,7 +3484,7 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": "^7.1",
+        "php": "^7.2",
         "ext-ctype": "*",
         "ext-dom": "*",
         "ext-gd": "*",

docs/index.md

@@ -25,13 +25,14 @@ spreadsheet file formats, like Excel and LibreOffice Calc.
 
 ## Software requirements
 
-PHP version 7.1 or newer to develop using PhpSpreadsheet. Other requirements, such as PHP extensions, are enforced by
+PHP version 7.2 or newer to develop using PhpSpreadsheet. Other requirements, such as PHP extensions, are enforced by
 composer. See the `require` section of [the composer.json file](https://github.com/PHPOffice/PhpSpreadsheet/blob/master/composer.json)
 for details.
 
 ### PHP version support
 
-Support for PHP versions will only be maintained for a period of six months beyond the end-of-life of that PHP version
+Support for PHP versions will only be maintained for a period of six months beyond the
+[end of life of that PHP version](https://www.php.net/eol.php).
 
 ## Installation
 

samples/index.php

@@ -3,7 +3,7 @@
 require_once 'Header.php';
 
 $requirements = [
-    'PHP 7.1.0' => version_compare(PHP_VERSION, '7.1.0', '>='),
+    'PHP 7.2.0' => version_compare(PHP_VERSION, '7.2.0', '>='),
     'PHP extension XML' => extension_loaded('xml'),
     'PHP extension xmlwriter' => extension_loaded('xmlwriter'),
     'PHP extension mbstring' => extension_loaded('mbstring'),

src/PhpSpreadsheet/Settings.php

@@ -28,8 +28,6 @@ class Settings
      * Allow/disallow libxml_disable_entity_loader() call when not thread safe.
      * Default behaviour is to do the check, but if you're running PHP versions
      *      7.2 < 7.2.1
-     *      7.1 < 7.1.13
-     *      7.0 < 7.0.27
      * then you may need to disable this check to prevent unwanted behaviour in other threads
      * SECURITY WARNING: Changing this flag is not recommended.
      *
@@ -119,8 +117,6 @@ class Settings
      * Allow/disallow libxml_disable_entity_loader() call when not thread safe.
      * Default behaviour is to do the check, but if you're running PHP versions
      *      7.2 < 7.2.1
-     *      7.1 < 7.1.13
-     *      7.0 < 7.0.27
      * then you may need to disable this check to prevent unwanted behaviour in other threads
      * SECURITY WARNING: Changing this flag to false is not recommended.
      *