Drop test for php 5.4 and update README with badges

Author: moux2003

.travis.yml

@@ -14,11 +14,10 @@ matrix:
           # Minimum supported dependencies with the latest and oldest PHP version
         - php: 7.2
           env: COMPOSER_FLAGS="--prefer-stable --prefer-lowest" SYMFONY_DEPRECATIONS_HELPER="weak_vendors"
-        - php: 5.4
+        - php: 5.5
           env: COMPOSER_FLAGS="--prefer-stable --prefer-lowest" SYMFONY_DEPRECATIONS_HELPER="weak_vendors"
 
           # Test the latest stable release
-        - php: 5.4
         - php: 5.5
         - php: 5.6
         - php: 7.0

README.md

@@ -1,5 +1,9 @@
 # SwiftmailerSendGridBundle
 
+[![Latest Version](https://img.shields.io/github/release/expertcoder/SwiftmailerSendGridBundle.svg?style=flat-square)](https://github.com/janephp/janephp/releases)
+[![Software License](https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat-square)](LICENSE)
+[![Build Status](https://img.shields.io/travis/expertcoder/SwiftmailerSendGridBundle.svg?style=flat-square)](https://travis-ci.org/expertcoder/SwiftmailerSendGridBundle)
+
 Symfony 2/3 bundle for SendGrid. Utilizes the SendGrid PHP Library https://github.com/sendgrid/sendgrid-php 
 to make it compatiable with SwiftMailer.