restrict Node engine + enhance readme

Author: taktakpeops

README.md

@@ -1,5 +1,8 @@
 # jest-environment-browserstack
 
+[![Actions Status](https://github.com/taktakpeops/jest-environment-browserstack/workflows/Node%20CI/badge.svg)](https://github.com/taktakpeops/jest-environment-browserstack/actions) [![npm version](http://img.shields.io/npm/v/jest-environment-browserstack.svg?style=flat)](https://npmjs.org/package/jest-environment-browserstack "View this project on npm")
+
+
 Use Jest as test-runner for running your visual-tests and more using Browserstack.
 
 The current implementation supports only the W3C way for capabilities. More info: https://www.browserstack.com/automate/selenium-4

package-lock.json

@@ -9,6 +9,9 @@
     "type": "git",
     "url": "git+https://github.com/taktakpeops/jest-environment-browserstack.git"
   },
+  "engines": {
+    "node": ">= 10.15.0"
+  },
   "scripts": {
     "build": "tsc",
     "lint": "eslint --ext .ts src/*",
@@ -41,9 +44,9 @@
     "eslint": "~6.4.0",
     "eslint-config-prettier": "~6.3.0",
     "eslint-plugin-prettier": "~3.1.1",
-    "jest": "^24.9.0",
+    "jest": "~24.9.0",
     "prettier": "~1.18.2",
-    "ts-jest": "^24.1.0",
+    "ts-jest": "~24.1.0",
     "typescript": "~3.6.3"
   },
   "jest": {