chore: add test coverage badges (#120)

Co-authored-by: Lukasz Gornicki <lpgornicki@gmail.com>

Author: jonaslagoni

.github/workflows/coverall.yml

@@ -0,0 +1,25 @@
+on: 
+  push:
+    branches:
+      - master
+  pull_request_target:
+    types: [opened, reopened, synchronize, ready_for_review]
+name: Check test coverage 
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Setup Node.js
+      uses: actions/setup-node@v1
+      with:
+        node-version: 14
+    - name: npm install, run test
+      run: |
+        npm install
+        npm run test
+    - name: Coveralls
+      uses: coverallsapp/github-action@v1.1.2
+      with:
+        github-token: ${{ secrets.GITHUB_TOKEN }}

README.md

@@ -8,6 +8,7 @@
   <em>The official SDK for generating data models from JSON Schema and AsyncAPI spec</em>
 </p>
 
+[![Coverage Status](https://coveralls.io/repos/github/asyncapi/generator-model-sdk/badge.svg?branch=master)](https://coveralls.io/github/asyncapi/generator-model-sdk?branch=master)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
 [![All Contributors](https://img.shields.io/badge/all_contributors-4-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->

jest.config.js

@@ -1,7 +1,7 @@
 // eslint-disable-next-line no-undef
 module.exports = {
   coverageReporters: [
-    'json',
+    'json-summary',
     'lcov',
     'text'
   ],