Drop support for PHP 7.1 (#2014)

* Updated PHP requirement to 7.2

* Set wikimedia less version to 1.8

* Indentation fix on composer json

* Revert "Set wikimedia less version to 1.8"

This reverts commit 22d862fd98.

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        php: [7.1, 7.2, 7.3, 7.4]
+        php: [7.2, 7.3, 7.4]
         service: ['mysql:5.7', mariadb]
         prefix: ['', flarum_]
 
@@ -21,12 +21,6 @@ jobs:
             prefixStr: (prefix)
 
         exclude:
-          - php: 7.1
-            service: 'mysql:5.7'
-            prefix: flarum_
-          - php: 7.1
-            service: mariadb
-            prefix: flarum_
           - php: 7.2
             service: 'mysql:5.7'
             prefix: flarum_

composer.json

@@ -24,7 +24,7 @@
         "docs": "https://flarum.org/docs/"
     },
     "require": {
-        "php": ">=7.1",
+        "php": ">=7.2",
         "axy/sourcemap": "^0.1.4",
         "components/font-awesome": "5.9.*",
         "dflydev/fig-cookies": "^1.0.2",

src/Install/Installation.php

@@ -87,7 +87,7 @@ class Installation
     public function prerequisites(): Prerequisite\PrerequisiteInterface
     {
         return new Prerequisite\Composite(
-            new Prerequisite\PhpVersion('7.1.0'),
+            new Prerequisite\PhpVersion('7.2.0'),
             new Prerequisite\PhpExtensions([
                 'dom',
                 'gd',