make compatible with Laravel 6

.travis.yml

@@ -1,20 +1,39 @@
-language: php
+cache:
+    directories:
+        - $HOME/.composer/cache
 
-php:
-  - 7.2
-  - 7.3
+language: php
 
 env:
-  matrix:
-    - COMPOSER_FLAGS="--prefer-lowest"
-    - COMPOSER_FLAGS=""
+    global:
+        - COVERAGE=0
+
+matrix:
+    include:
+        - php: 7.2
+          env: LARAVEL='5.8.*' TESTBENCH='3.8.*' COMPOSER_FLAGS='--prefer-lowest'
+        - php: 7.2
+          env: LARAVEL='5.8.*' TESTBENCH='3.8.*' COMPOSER_FLAGS='--prefer-stable'
+        - php: 7.3
+          env: LARAVEL='5.8.*' TESTBENCH='3.8.*' COMPOSER_FLAGS='--prefer-lowest'
+        - php: 7.3
+          env: LARAVEL='5.8.*' TESTBENCH='3.8.*' COMPOSER_FLAGS='--prefer-stable'
+        - php: 7.2
+          env: LARAVEL='6.*' TESTBENCH='4.*' COMPOSER_FLAGS='--prefer-lowest'
+        - php: 7.2
+          env: LARAVEL='6.*' TESTBENCH='4.*' COMPOSER_FLAGS='--prefer-stable'
+        - php: 7.3
+          env: LARAVEL='6.*' TESTBENCH='4.*' COMPOSER_FLAGS='--prefer-lowest'
+        - php: 7.3
+          env: LARAVEL='6.*' TESTBENCH='4.*' COMPOSER_FLAGS='--prefer-stable'
+    fast_finish: true
 
 before_script:
-  - travis_retry composer self-update
-  - travis_retry composer update ${COMPOSER_FLAGS} --no-interaction --prefer-source
+    - composer config discard-changes true
 
-script:
-  - phpunit --coverage-text --coverage-clover=coverage.clover
+before_install:
+    - travis_retry composer self-update
+    - travis_retry composer require "laravel/framework:${LARAVEL}" "orchestra/testbench:${TESTBENCH}" --no-interaction --no-update
 
-after_script:
-  - php vendor/bin/ocular code-coverage:upload --format=php-clover coverage.clover
+install:
+    - travis_retry composer update ${COMPOSER_FLAGS} --prefer-dist --no-interaction --no-suggest

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes to `laravel-translatable` will be documented in this file
 
+## 4.2.0 - 2019-09-04
+
+- make compatible with Laravel 6
+
 ## 4.1.4 - 2019-08-28
 
 - re-added the `translatable.fallback_local` config which overrule `app.fallback_local` (see https://github.com/spatie/laravel-translatable/issues/170)

composer.json

@@ -38,7 +38,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^8.0",
-        "orchestra/testbench": "~3.8.0",
+        "orchestra/testbench": "~3.8.0|^4.0",
         "mockery/mockery": "^1.0"
     },
     "autoload": {