docs(readme): Add build and coverage badges

Author: nodkz

README.md

@@ -1,5 +1,7 @@
 # graphql-compose-connection
 
+[![travis build](https://img.shields.io/travis/nodkz/graphql-compose-connection.svg)](https://travis-ci.org/nodkz/graphql-compose-connection)
+[![codecov coverage](https://img.shields.io/codecov/c/github/nodkz/graphql-compose-connection.svg)](https://codecov.io/github/nodkz/graphql-compose-connection)
 [![](https://img.shields.io/npm/v/graphql-compose-connection.svg)](https://www.npmjs.com/package/graphql-compose-connection)
 [![npm](https://img.shields.io/npm/dt/graphql-compose-connection.svg)](https://www.npmjs.com/package/graphql-compose-connection)
 [![Join the chat at https://gitter.im/graphql-compose/Lobby](https://badges.gitter.im/nodkz/graphql-compose.svg)](https://gitter.im/graphql-compose/Lobby)