Add test coverage with istanbul

.gitignore

@@ -9,3 +9,7 @@ lib
 
 # Logs
 npm-debug.log
+
+# Istanbul coverage
+.nyc_output
+coverage/

package.json

@@ -6,7 +6,7 @@
         "url": "https://www.matchilling.com"
     },
     "homepage": "https://botlang.org",
-    "version": "0.1.0",
+    "version": "0.1.1",
     "license": "GPL-3.0",
     "description": "Botlang implementation for JavaScript",
     "keywords": [
@@ -31,16 +31,19 @@
     "devDependencies": {
         "babel-cli": "^6.23.0",
         "babel-core": "^6.24.0",
+        "babel-plugin-istanbul": "^4.1.1",
         "babel-preset-es2015": "^6.22.0",
         "chai": "^3.5.0",
         "esdoc": "^0.5.2",
         "eslint": "^3.17.0",
         "eslint-config-matchilling": "^2.1.0",
         "eslint-plugin-import": "^2.2.0",
-        "mocha": "^3.2.0"
+        "mocha": "^3.2.0",
+        "nyc": "^10.2.0"
     },
     "scripts": {
         "compile": "./node_modules/.bin/babel --minified --no-comments --out-dir lib/ src/",
+        "coverage": "./node_modules/.bin/nyc --check-coverage npm test",
         "dev": "./node_modules/.bin/mocha --compilers js:babel-core/register --recursive --watch test/",
         "docs:make": "./node_modules/.bin/esdoc -c .esdoc.json",
         "eslint": "./node_modules/.bin/eslint src/",
@@ -53,6 +56,8 @@
         ]
     },
     "babel": {
-        "presets": ["es2015"]
+        "presets": [
+            "es2015"
+        ]
     }
 }