bump minimum php version to 5.6 and update test libs

.travis.yml

@@ -1,24 +1,17 @@
 language: php
 php:
-  - 5.4
-  - 5.5
   - 5.6
   - 7.0
   - 7.1
   - 7.2
-
-env:
-  global:
-    - CURRENT_DIR=`pwd`
+  - 7.3
 
 install:
   - composer install --dev --no-interaction
 
 script:
   - mkdir -p build/logs
-  - cd tests
-  - ../vendor/bin/phpunit --coverage-clover ../build/logs/clover.xml --configuration phpunit.xml
+  - vendor/bin/phpunit --coverage-clover build/logs/clover.xml --configuration tests/phpunit.xml
 
 after_script:
- - cd $CURRENT_DIR
- - php vendor/bin/coveralls -v
+  - vendor/bin/php-coveralls -v

composer.json

@@ -9,11 +9,11 @@
 		}
 	],
 	"require"          : {
-		"php": ">=5.3"
+		"php": ">=5.6"
 	},
 	"require-dev"      : {
-		"satooshi/php-coveralls": "v1.0.0",
-		"phpunit/phpunit": "^4.8"
+		"php-coveralls/php-coveralls": "v2.1.0",
+		"phpunit/phpunit": "^5.7"
 	},
 	"autoload"         : {
 		"psr-4": {

tests/phpunit.xml

@@ -3,4 +3,10 @@
 	<testsuite name='Stream'>
 		<directory suffix='.php'>./</directory>
 	</testsuite>
+
+	<filter>
+		<whitelist Stream="true">
+			<directory suffix=".php">../src</directory>
+		</whitelist>
+	</filter>
 </phpunit>