Drop support for PHP 5.6 (#36)

Author: nclsHart

.travis.yml

@@ -3,7 +3,6 @@ language: php
 sudo: false
 
 php:
-  - 5.6
   - 7.0
   - 7.1
   - 7.2
@@ -15,11 +14,6 @@ env:
 
 matrix:
   fast_finish: true
-  exclude:
-    - php: 7.2
-      env: DEPS=normal
-    - php: 7.2
-      env: DEPS=lowest
 
 branches:
   only:

composer.json

@@ -10,12 +10,12 @@
         }
     ],
     "require" : {
-        "php": ">=5.6",
+        "php": ">=7.0",
         "swiftmailer/swiftmailer": "^5.1",
         "tijsverkoyen/css-to-inline-styles": "^2.1"
     },
     "require-dev" : {
-        "phpunit/phpunit": "^4 || ^5 || ^6",
+        "phpunit/phpunit": "^5.7.10 || ^6.0",
         "symfony/css-selector": "^2.0.5|^3.0"
     },
     "autoload": {
@@ -30,7 +30,7 @@
     },
     "config": {
         "platform": {
-            "php": "5.6"
+            "php": "7.0"
         }
     }
 }