Add Travis + CodeCov shields

Author: wilzbach

README.md

@@ -1,5 +1,8 @@
 # Dlang-Bot
 
+[![Travis build status](https://travis-ci.org/dlang-bots/dlang-bot.svg?branch=master)](https://travis-ci.org/dlang-bots/dlang-bot)
+[![Codecov](https://img.shields.io/codecov/c/github/dlang-bots/dlang-bot/master.svg)](https://codecov.io/gh/dlang-bots/dlang-bot)
+
 <img alt="dlang-bot" height="200px" src="public/img/dlang_bot.png" />
 
 Features