Updated travis.yml

Author: MaximilianKresse

.travis.coverage.sh

@@ -4,10 +4,9 @@ php:
   - '7.1'
 
 before_script:
-  - composer install
+  - composer selfupdate
 
-script:
-  - vendor/bin/phpunit --verbose --coverage-text --coverage-clover=clover.xml --colors
+install: composer update --prefer-dist --no-interaction
 
-after_script:
-  - sh .travis.coverage.sh
+script:
+  - vendor/bin/phpunit --colors