add coverage and switch to jest

Author: amalfra

.eslintrc.json

@@ -4,7 +4,7 @@
     "ecmaVersion": 2020
   },
   "env": {
-    "mocha": true,
+    "jest": true,
     "es6": true,
     "node": true
   },

.github/workflows/test.yml

@@ -15,3 +15,5 @@ jobs:
           node-version: ${{ matrix.node-version }}
       - run: npm ci
       - run: npm test
+      - name: Coveralls
+        uses: coverallsapp/github-action@master