Merge pull request #82 from DataValues/travis04x

Fix Travis builds of 0.4.x branch

Author: Ladsgroup

.travis.yml

@@ -1,12 +1,9 @@
 language: php
 
 php:
-  - 5.3
-  - 5.4
-  - 5.5
   - 5.6
   - 7
-  - hhvm
+  - hhvm-3.18
 
 before_script:
   - travis_retry composer install --prefer-source

composer.json

@@ -27,6 +27,9 @@
 		"data-values/data-values": "~2.0|~1.0|~0.1",
 		"data-values/interfaces": "~0.2.0|^0.1.5"
 	},
+	"require-dev": {
+		"phpunit/phpunit": "~5.7"
+	},
 	"extra": {
 		"branch-alias": {
 			"dev-master": "0.4.x-dev"