Fix travis builds

.travis.yml

@@ -1,20 +1,22 @@
 language: php
 
 php:
-  - 5.4
-  - 5.5
-  - 5.6
-  - 7.0
-  - 7.1
-  - 7.2
+  - '5.4'
+  - '5.5'
+  - '5.6'
+  - '7.0'
+  - '7.1'
+  - '7.2'
+  - '7.3'
 
 matrix:
   include:
-    - php: 5.3
+    - php: '5.3'
       dist: precise
 
 before_script:
   - travis_retry composer self-update
+  - travis_retry composer global require hirak/prestissimo
   - travis_retry composer install --no-interaction --prefer-source --dev
   - travis_retry phpenv rehash
 
@@ -25,4 +27,4 @@ script:
   - mkdir -p build/logs
 
 after_script:
-  - php vendor/bin/coveralls -v
+  - php vendor/bin/php-coveralls -v

composer.json

@@ -18,9 +18,9 @@
         "php": ">=5.3"
     },
     "require-dev": {
-        "phpunit/phpunit": "@stable",
-        "squizlabs/php_codesniffer": "@stable",
-        "satooshi/php-coveralls": "@stable",
+        "phpunit/phpunit": "^5.0|^6.0|^7.0",
+        "squizlabs/php_codesniffer": "^3.4",
+        "php-coveralls/php-coveralls": "^2.1",
         "symfony/var-dumper": "@stable"
     }
 }