Add php linting via travis

Author: reedy

.travis.yml

@@ -0,0 +1,13 @@
+language: php
+php:
+  - "7.0"
+  - "7.1"
+  - "7.2"
+  - "7.3"
+env:
+  global:
+    - COMPOSER_DISABLE_XDEBUG_WARN=1
+install:
+  - composer install
+script:
+  - composer test

composer.json

@@ -0,0 +1,15 @@
+{
+    "name": "emoncms/app",
+    "homepage": "https://emoncms.org",
+    "support": {
+        "forum": "https://community.openenergymonitor.org/"
+    },
+    "require-dev": {
+        "jakub-onderka/php-parallel-lint": "1.0.0"
+    },
+    "scripts": {
+        "test": {
+            "parallel-lint . --exclude vendor"
+        }
+    }
+}