Badges in README updated [skip ci]

Author: svyatov

README.md

@@ -2,8 +2,8 @@
 
 Simple wrapper around standard Net::HTTP library
 
-[![Gem Version](https://badge.fury.io/rb/http_wrapper.png)](http://badge.fury.io/rb/http_wrapper)
-[![Build Status](https://travis-ci.org/svyatov/http_wrapper.png)](https://travis-ci.org/svyatov/http_wrapper)
+[![Gem Version](https://badge.fury.io/rb/http_wrapper.svg)](https://badge.fury.io/rb/http_wrapper)
+[![Build Status](https://travis-ci.org/svyatov/http_wrapper.svg?branch=master)](https://travis-ci.org/svyatov/http_wrapper)
 [![Maintainability](https://api.codeclimate.com/v1/badges/41f8e8c507907ea20e2b/maintainability)](https://codeclimate.com/github/svyatov/http_wrapper/maintainability)
 [![Test Coverage](https://api.codeclimate.com/v1/badges/41f8e8c507907ea20e2b/test_coverage)](https://codeclimate.com/github/svyatov/http_wrapper/test_coverage)