CodeCov badge to master. (#147)

# Describe Request

CodeCov badge to master.

Fixed # (issue)

# Change Type

Link change.

README.md

@@ -1,4 +1,4 @@
-[![GoDoc](https://godoc.org/github.com/cinar/indicator/v2?status.svg)](https://godoc.org/github.com/cinar/indicator/v2) [![License](https://img.shields.io/badge/License-AGPLv3-blue.svg)](https://opensource.org/licenses/AGPLv3) [![Go Report Card](https://goreportcard.com/badge/github.com/cinar/indicator/v2)](https://goreportcard.com/report/github.com/cinar/indicator/v2) ![Go CI](https://github.com/cinar/indicator/actions/workflows/ci.yml/badge.svg) [![codecov](https://codecov.io/gh/cinar/indicator/branch/v2/graph/badge.svg?token=MB7L69UAWM)](https://codecov.io/gh/cinar/indicator)
+[![GoDoc](https://godoc.org/github.com/cinar/indicator/v2?status.svg)](https://godoc.org/github.com/cinar/indicator/v2) [![License](https://img.shields.io/badge/License-AGPLv3-blue.svg)](https://opensource.org/licenses/AGPLv3) [![Go Report Card](https://goreportcard.com/badge/github.com/cinar/indicator/v2)](https://goreportcard.com/report/github.com/cinar/indicator/v2) ![Go CI](https://github.com/cinar/indicator/actions/workflows/ci.yml/badge.svg) [![codecov](https://codecov.io/gh/cinar/indicator/graph/badge.svg?token=MB7L69UAWM)](https://codecov.io/gh/cinar/indicator)
 
 Indicator Go
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