Fix coverage badge.

Author: kshetline

README.md

@@ -2,7 +2,7 @@
 
 Not all days are 24 hours. Some are 23 hours, or 25, or even 23.5 or 24.5 or 47 hours. How about a Thursday followed directly by a Saturday, giving Friday the slip? Or a September only 19 days long? This is a date/time library for handling both day-to-day situations (so to speak) and some weird ones too.
 
-[![npm](https://img.shields.io/npm/v/@tubular/time.svg)](https://www.npmjs.com/package/@tubular/time/) [![Build Status](https://img.shields.io/travis/kshetline/tubular_time/master.svg)](https://travis-ci.com/github/kshetline/tubular_time/) [![Coverage Status](https://coveralls.io/repos/github/kshetline/tubular_time/badge.svg)](https://coveralls.io/github/kshetline/tubular_time) [![npm downloads](https://img.shields.io/npm/dm/@tubular/time.svg)](https://npmjs.org/package/@tubular/time/) ![npm bundle size (scoped)](https://img.shields.io/bundlephobia/min/@tubular/time)  ![license](https://img.shields.io/badge/licence-mit-informational)
+[![npm](https://img.shields.io/npm/v/@tubular/time.svg)](https://www.npmjs.com/package/@tubular/time/) [![Build Status](https://img.shields.io/travis/kshetline/tubular_time/master.svg)](https://travis-ci.com/github/kshetline/tubular_time/) [![Coverage Status](https://coveralls.io/repos/github/kshetline/tubular_time/badge.svg?branch=master)](https://coveralls.io/github/kshetline/tubular_time) [![npm downloads](https://img.shields.io/npm/dm/@tubular/time.svg)](https://npmjs.org/package/@tubular/time/) ![npm bundle size (scoped)](https://img.shields.io/bundlephobia/min/@tubular/time)  ![license](https://img.shields.io/badge/licence-mit-informational)
 
 ## Key features<!-- omit in toc -->