Add travis

Author: paulhenri-l

.travis.yml

@@ -0,0 +1,11 @@
+language: php
+
+php:
+  - '7.1'
+  - '7.2'
+  - '7.3'
+
+before_script:
+  - composer install
+
+script: phpunit

README.md

@@ -1,5 +1,7 @@
 # Laravel RespondTo
 
+![Travis](https://api.travis-ci.org/paulhenri-l/laravel-respond-to.svg?branch=master)
+
 This library will provide you with rails like `respond_to` functionality. This
 feature allows a controller action to return different responses according to
 the request `Accept` header (the format).
@@ -34,8 +36,8 @@ class MyController
 }
 ```
 
-This controller is now able to respond to `html`, `json` and `txt` requests with
-different responses.
+This controller is now able to respond to different formats with different 
+responses.
 
 *Each call to the `to` function must be followed by a `with` or `withView`
 call.*

composer.json

@@ -10,6 +10,7 @@
         }
     ],
     "require": {
+        "php": "^7.1",
         "laravel/framework": "^5.8"
     },
     "require-dev": {