fix: integrate with coveralls and add coveralls badge

.releaserc.json

@@ -9,6 +9,11 @@
         "npmPublish": true
       }
     ],
-    "@semantic-release/git"
+    [
+      "@semantic-release/git",
+      {
+        "assets": ["CHANGELOG.md", "package.json"]
+      }
+    ]
   ]
 }

.travis.yml

@@ -3,6 +3,9 @@ node_js:
   - 12
 jobs:
   include:
+    - stage: Produce Coverage
+      node_js: node
+      script: npm run coveralls
     - stage: release
       node_js: lts/*
       script: npm run build

README.md

@@ -2,6 +2,7 @@
 
 [![Build status](https://badgen.net/travis/pjchender/react-use-opentok)](https://travis-ci.com/pjchender/react-use-opentok)
 [![version](https://img.shields.io/npm/v/react-use-opentok.svg)](https://www.npmjs.com/package/react-use-opentok)
+[![Coverage Status](https://coveralls.io/repos/github/pjchender/react-use-opentok/badge.svg?branch=master)](https://coveralls.io/github/pjchender/react-use-opentok?branch=master)
 [![license](https://img.shields.io/github/license/pjchender/react-use-opentok.svg)](https://github.com/pjchender/react-use-opentok/blob/master/LICENSE)
 [![All Contributors](https://img.shields.io/badge/all_contributors-2-orange.svg)](#contributors)