Fix #51

And reformat the package.json while I'm at it.

.nycrc.json

@@ -0,0 +1,3 @@
+{
+    "extends": "@istanbuljs/nyc-config-typescript"
+}

README.md

@@ -25,4 +25,6 @@ $> npm run clean
 ```shell script
 # Run tests
 $> npm test
+# Run tests with coverage
+$> npm run coverage
 ```

package.json

@@ -12,12 +12,14 @@
         "clean": "grunt clean",
         "dev": "grunt dev",
         "deploy": "grunt deploy",
-    "test": "mocha -r ts-node/register src/**/*.spec.ts"
+        "test": "mocha -r ts-node/register src/**/*.spec.ts",
+        "coverage": "nyc npm run test"
     },
     "dependencies": {
         "js-cookie": "^2.2.1"
     },
     "devDependencies": {
+        "@istanbuljs/nyc-config-typescript": "^0.1.3",
         "@types/chai": "^4.2.4",
         "@types/js-cookie": "^2.2.4",
         "@types/mocha": "^5.2.7",
@@ -29,6 +31,7 @@
         "grunt-text-replace": "^0.4.0",
         "grunt-webpack": "^3.1.3",
         "mocha": "^6.2.2",
+        "nyc": "^14.1.1",
         "ts-loader": "^6.2.1",
         "ts-node": "^8.4.1",
         "typescript": "^3.7.2",