[core] Drop php 5.6 and php 7.0 support (RSS-Bridge#2224)

.github/workflows/lint.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        php-versions: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4']
+        php-versions: ['7.1', '7.2', '7.3', '7.4']
     steps:
       - uses: actions/checkout@v2
       - uses: shivammathur/setup-php@v2
@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        php-versions: ['5.6', '7.4']
+        php-versions: ['7.1', '7.4']
     steps:
       - uses: actions/checkout@v2
       - uses: shivammathur/setup-php@v2

.github/workflows/tests.yml

@@ -7,19 +7,6 @@ on:
     branches: [ master ]
 
 jobs:
-  phpunit6:
-    runs-on: ubuntu-20.04
-    strategy:
-      matrix:
-        php-versions: ['7.0', '7.1', '7.2']
-    steps:
-      - uses: actions/checkout@v2
-      - uses: shivammathur/setup-php@v2
-        with:
-          php-version: ${{ matrix.php-versions }}
-      - run: composer global require phpunit/phpunit ^6
-      - run: phpunit --configuration=phpunit.xml --include-path=lib/
-
   phpunit7:
     runs-on: ubuntu-20.04
     strategy:

README.md

@@ -57,7 +57,7 @@ RSS-Bridge hashtag (#rss-bridge) search on Twitter, in Atom format (as displayed
 Requirements
 ===
 
-RSS-Bridge requires PHP 5.6 or higher with following extensions enabled:
+RSS-Bridge requires PHP 7.1 or higher with following extensions enabled:
 
   - [`openssl`](https://secure.php.net/manual/en/book.openssl.php)
   - [`libxml`](https://secure.php.net/manual/en/book.libxml.php)

composer.json

@@ -21,7 +21,7 @@
         "rss": "https://github.com/RSS-Bridge/rss-bridge/commits/master.atom"
     },
     "require": {
-        "php": ">=5.6",
+        "php": ">=7.1",
         "ext-mbstring": "*",
         "ext-curl": "*",
         "ext-openssl": "*",
@@ -30,7 +30,7 @@
         "ext-json": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6 || ^7"
+        "phpunit/phpunit": "^7"
     },
     "suggest": {
         "ext-memcached": "Allows to use memcached as cache type",