Fix GSM 03.38 charset (#5)

Fix to avoid removing valid characters
Add more tests
Fix travis

.travis.yml

@@ -6,6 +6,6 @@ php:
   - hhvm
 
 before_script:
-  - composer install --dev
+  - composer install
 
-script: phpunit
+script: vendor/bin/phpunit

README.md

@@ -5,12 +5,12 @@ Character counter for SMS Messages
 [![Build Status](https://img.shields.io/travis/instasent/sms-counter-php.svg?style=flat-square)](https://travis-ci.org/instasent/sms-counter-php)
 [![SensioLabsInsight](https://img.shields.io/sensiolabs/i/0a2fa87a-0287-46f6-b8b5-818b44a2b9f9.svg?style=flat-square)](https://insight.sensiolabs.com/projects/0a2fa87a-0287-46f6-b8b5-818b44a2b9f9)
 
-##Usage
+## Usage
 
 ```php
 use Instasent\SMSCounter\SMSCounter;
 
-$smsCounter = new SMSCounter;
+$smsCounter = new SMSCounter();
 $smsCounter->count('some-string-to-be-counted');
 ```
 
@@ -26,23 +26,32 @@ stdClass Object
 )
 ```
 
-##Installation
+You can sanitize your text to be a valid GSM 03.38 charset
+
+```php
+use Instasent\SMSCounter\SMSCounter;
+
+$smsCounter = new SMSCounter();
+$smsCounter->sanitizeToGSM('dadáó'); //return dadao
+```
+
+## Installation
 
 `sms-counter-php` is available via [composer](http://getcomposer.org) on [packagist](https://packagist.org/packages/instasent/sms-counter-php).
 
 ```json
 {
-"require": {
-"instasent/sms-counter-php": "dev-master"
-}
+    "require": {
+       "instasent/sms-counter-php": "^0.3"
+    }
 }
 ```
 
-##License
+## License
 
 SMS Counter (PHP) is released under the [MIT License](LICENSE-MIT.md)
 
-###Mentions
+### Mentions
 
 * Original idea : [danxexe/sms-counter](https://github.com/danxexe/sms-counter)
 * Fork Idea from: [acpmasquerade/sms-counter-php](https://github.com/acpmasquerade/sms-counter-php)