update README

README.md

@@ -4,7 +4,9 @@
 [![Open Source Love](https://badges.frapsoft.com/os/v1/open-source.png?v=103)](https://github.com/ellerbrock/open-source-badges/)
 [![Build status](https://ci.appveyor.com/api/projects/status/jv28205majdbvvj0?svg=true)](https://ci.appveyor.com/project/Dentrax/data-structures-with-go)
 [![Build Status](https://travis-ci.org/Dentrax/Data-Structures-with-Go.svg?branch=master)](https://travis-ci.org/Dentrax/Data-Structures-with-Go)
+[![codecov](https://codecov.io/gh/Dentrax/Data-Structures-with-Go/branch/master/graph/badge.svg)](https://codecov.io/gh/Dentrax/Data-Structures-with-Go)
 [![Go Report Card](https://goreportcard.com/badge/github.com/Dentrax/Data-Structures-with-Go)](https://goreportcard.com/report/github.com/Dentrax/Data-Structures-with-Go)
+[![Sourcegraph](https://img.shields.io/badge/view%20on-Sourcegraph-brightgreen.svg)](https://sourcegraph.com/github.com/Dentrax/Data-Structures-with-Go)
 
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