docs: update build badge and add coverage scripts

.gitignore

@@ -1,5 +1,6 @@
 node_modules/
 .changelog
+coverage
 
 # Numerous always-ignore extensions
 *.diff

.travis.yml

@@ -1,3 +1,7 @@
 language: node_js
 node_js:
   - 12
+
+script:
+  - npm run lint
+  - npx jest --coverage && coveralls < coverage/lcov.info

README.md

@@ -3,7 +3,7 @@
 A JavaScript plugin to help preserve an element's scroll position.
 
 [![npm version](https://img.shields.io/npm/v/scroll-stash.svg)](https://www.npmjs.com/package/scroll-stash)
-[![Build Status](https://img.shields.io/travis/sebnitu/scroll-stash.svg)](https://travis-ci.org/sebnitu/scroll-stash)
+[![Build Status](https://travis-ci.org/sebnitu/scroll-stash.svg?branch=master)](https://travis-ci.org/sebnitu/scroll-stash)
 [![devDependency Status](https://img.shields.io/david/dev/sebnitu/scroll-stash.svg)](https://david-dm.org/sebnitu/scroll-stash?type=dev)
 
 ## Installation

package.json

@@ -17,7 +17,10 @@
     "clean": "del dist",
     "scripts": "rollup -c",
     "watch": "nodemon -e js -x 'npm run scripts' -i dist",
+    "lint": "eslint index.js",
+    "lint:fix": "eslint index.js --fix",
     "test": "jest",
+    "test:coverage": "jest --coverage",
     "test:watch": "jest --watch",
     "changelog": "conventional-changelog -p angular"
   },
@@ -41,6 +44,7 @@
     "babel-jest": "^26.0.1",
     "concurrently": "^5.2.0",
     "conventional-changelog-cli": "^2.0.34",
+    "coveralls": "^3.1.0",
     "del-cli": "^3.0.1",
     "eslint": "^7.2.0",
     "eslint-plugin-jest": "^23.13.2",