Support PHP 7.2 (#30)

* Add PHP 7.2 to the build matrix on Travis CI

* Install various PHPUnit versions

* Exclude PHPUnit 4 from PHP 7.2 build

Author: hkdobrev

.travis.yml

@@ -7,6 +7,7 @@ php:
   - 5.6
   - 7.0
   - 7.1
+  - 7.2
 
 env:
   - DEPS=normal
@@ -15,6 +16,11 @@ env:
 
 matrix:
   fast_finish: true
+  exclude:
+    - php: 7.2
+      env: DEPS=normal
+    - php: 7.2
+      env: DEPS=lowest
 
 branches:
   only:

composer.json

@@ -15,7 +15,7 @@
         "tijsverkoyen/css-to-inline-styles": "^2.1"
     },
     "require-dev" : {
-        "phpunit/phpunit": "^4.0|^5.0",
+        "phpunit/phpunit": "^4 || ^5 || ^6",
         "symfony/css-selector": "^2.0.5|^3.0"
     },
     "autoload": {