docs: update coveralls link

Author: calintamas

README.md

@@ -3,7 +3,7 @@
 [![npm version](https://img.shields.io/npm/v/react-native-toast-message)](https://www.npmjs.com/package/react-native-toast-message)
 [![npm downloads](https://img.shields.io/npm/dw/react-native-toast-message)](https://www.npmjs.com/package/react-native-toast-message)
 [![Build](https://github.com/calintamas/react-native-toast-message/workflows/tests/badge.svg)](https://github.com/calintamas/react-native-toast-message/actions?query=workflow%3Atests)
-[![Coverage Status](https://coveralls.io/repos/github/calintamas/react-native-toast-message/badge.svg?branch=master)](https://coveralls.io/github/calintamas/react-native-toast-message?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/calintamas/react-native-toast-message/badge.svg?branch=master)](https://coveralls.io/github/calintamas/react-native-toast-message?branch=main)
 [![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg)](https://github.com/prettier/prettier)
 
 Animated toast message component for React Native.