minor update to README & Travis fix

.travis.yml

@@ -6,6 +6,10 @@ php:
   - 5.6
   - hhvm
 
+before_script:
+  - composer selfupdate
+  - composer install
+
 after_script:
   - vendor/bin/test-reporter
 

README.md

@@ -18,6 +18,10 @@ Unirest is a set of lightweight HTTP libraries available in multiple languages,
 * Customizable default headers for every request (DRY)
 * Automatic JSON parsing into a native object for JSON responses
 
+## Requirements
+
+- [cURL](http://php.net/manual/en/book.curl.php)
+
 ## Installation
 
 ### Using [Composer](https://getcomposer.org)
@@ -25,7 +29,6 @@ Unirest is a set of lightweight HTTP libraries available in multiple languages,
 To install unirest-php with Composer, just add the following to your `composer.json` file:
 
 ```json
-// composer.json
 {
     "require-dev": {
         "mashape/unirest-php": "2.*"