Refactor module in TypeScript (#28)

package.json

@@ -16,10 +16,15 @@
     "node": ">=4"
   },
   "scripts": {
-    "test": "xo && ava"
+    "lint": "tslint --project .",
+    "build": "tsc",
+    "test": "npm run lint && npm run build && ava dist/tests",
+    "prepublish": "npm run build && del dist/tests"
   },
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
   "files": [
-    "index.js"
+    "dist"
   ],
   "keywords": [
     "type",
@@ -43,8 +48,13 @@
     "compare"
   ],
   "devDependencies": {
+    "@types/jsdom": "^2.0.31",
+    "@types/node": "^8.0.47",
     "ava": "*",
+    "del-cli": "^1.1.0",
     "jsdom": "^9.12.0",
-    "xo": "*"
+    "tslint": "^5.8.0",
+    "tslint-xo": "^0.2.1",
+    "typescript": "^2.6.1"
   }
 }