Updated dependencies.

Author: prwater

.travis.yml

@@ -1,9 +1,8 @@
 language: php
 php:
-  - '7.1'
-  - '7.2'
   - '7.3'
-  
+  - '7.4'
+
 install:
   - composer self-update
   - composer update

composer.json

@@ -8,11 +8,11 @@
   "type": "library",
   "license": "MIT",
   "require": {
-    "php": ">=7.1.0"
+    "php": ">=7.3.0"
   },
   "require-dev": {
-    "phing/phing": "^2.0.0",
-    "phpunit/phpunit": "^7.0.0 || ^8.0.0"
+    "phing/phing": "^2.0",
+    "phpunit/phpunit": "^9.0"
   },
   "autoload": {
     "psr-4": {