Add PHP CodeSniffer checks

.travis.yml

@@ -0,0 +1,20 @@
+sudo: false
+
+language: php
+
+matrix:
+  fast_finish: true
+  include:
+    - php: 5.6
+      env:
+        - EXECUTE_CS_CHECK=true
+
+before_script:
+  - composer self-update
+  - composer install --prefer-source --no-scripts
+
+script:
+  - if [[ $EXECUTE_CS_CHECK == 'true' ]]; then ./vendor/bin/phpcs ; fi
+
+notifications:
+  email: true

composer.json

@@ -14,7 +14,8 @@
         "zendframework/zend-expressive": "^0.2"
     },
     "require-dev": {
-        "composer/composer": "1.0.0-alpha10"
+        "composer/composer": "1.0.0-alpha10",
+        "squizlabs/php_codesniffer": "^2.3"
     },
     "autoload": {
         "psr-4": {

phpcs.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0"?>
+<ruleset name="Zend Framework coding standard">
+    <description>Zend Framework coding standard</description>
+
+    <!-- display progress -->
+    <arg value="p"/>
+    <arg name="colors"/>
+
+    <!-- inherit rules from: -->
+    <rule ref="PSR2"/>
+    <rule ref="Generic.Arrays.DisallowLongArraySyntax"/>
+    <rule ref="Squiz.WhiteSpace.SuperfluousWhitespace">
+        <properties>
+            <property name="ignoreBlankLines" value="false"/>
+        </properties>
+    </rule>
+
+    <!-- Paths to check -->
+    <file>src</file>
+    <file>test</file>
+</ruleset>