Updated travis php and laravel versions

Author: Tim Helfensdörfer

.travis.yml

@@ -1,26 +1,11 @@
 language: php
 
 php:
-- '7.0'
-- '7.1'
 - '7.2'
 - '7.3'
 
 env:
-- LARAVEL=5.5.*
-- LARAVEL=5.6.*
-- LARAVEL=5.7.*
-- LARAVEL=5.8.*
-
-matrix:
-  exclude:
-    - php: '7.0'
-      env: LARAVEL=5.6.*
-    - php: '7.0'
-      env: LARAVEL=5.7.*
-    - php: '7.0'
-      env: LARAVEL=5.8.*
-  fast_finish: true
+- LARAVEL=^6.0
 
 sudo: false