update travis

Author: pulkitjalan

.travis.yml

@@ -1,17 +1,35 @@
-sudo: false
 language: php
 
-php:
-  - 5.4
-  - 5.5.9
-  - 5.5
-  - 5.6
-  - 7.0
-  - hhvm
+cache:
+  directories:
+    - $HOME/.composer/cache
 
-before_script:
+matrix:
+  fast_finish: true
+  include:
+    - php: 7.2
+      env: LARAVEL='5.8.*' COMPOSER_FLAGS='--prefer-lowest'
+    - php: 7.2
+      env: LARAVEL='5.8.*' COMPOSER_FLAGS='--prefer-stable'
+    - php: 7.3
+      env: LARAVEL='5.8.*' COMPOSER_FLAGS='--prefer-lowest'
+    - php: 7.3
+      env: LARAVEL='5.8.*' COMPOSER_FLAGS='--prefer-stable'
+    - php: 7.2
+      env: LARAVEL='6.*' COMPOSER_FLAGS='--prefer-lowest'
+    - php: 7.2
+      env: LARAVEL='6.*' COMPOSER_FLAGS='--prefer-stable'
+    - php: 7.3
+      env: LARAVEL='6.*' COMPOSER_FLAGS='--prefer-lowest'
+    - php: 7.3
+      env: LARAVEL='6.*' COMPOSER_FLAGS='--prefer-stable'
+
+before_install:
   - travis_retry composer self-update
-  - travis_retry composer install --no-interaction --prefer-source --dev
+  - travis_retry composer require --no-update --no-interaction "illuminate/support:${LARAVEL}"
+
+install:
+  - travis_retry composer update ${COMPOSER_FLAGS} --prefer-dist --no-interaction --no-suggest
 
 script:
   - phpunit --coverage-text --coverage-clover=coverage.clover