update travis build matrix (drop 7.0, build up to 7.4, drop nightly)

Author: Douglas Greenshields

.travis.yml

@@ -1,21 +1,17 @@
 language: php
 
 php:
-    - 7.0
     - 7.1
     - 7.2
-    - nightly
-
-matrix:
-    allow_failures:
-        php: nightly
+    - 7.3
+    - 7.4
 
 before_script: composer install --dev --prefer-source
 
 script:
     - vendor/bin/phpunit -v
 
-dist: trusty
+dist: xenial
 
 notifications:
   email: "[email protected]"

composer.json

@@ -22,7 +22,7 @@
     "require-dev": {
         "symfony/console": "~2.1|~3.0",
         "guzzlehttp/guzzle": "~6.1",
-        "phpunit/phpunit": "^6"
+        "phpunit/phpunit": "^7"
     },
     "suggest": {
         "symfony/console": "To use CLI OEmbed scripts.",