Improving build and release (#19)

.gitignore

@@ -1,4 +1,4 @@
 node_modules
 /lib
 /coverage
-.idea
+.idea

.nvmrc

@@ -0,0 +1 @@
+14.15.1

package.json

@@ -9,6 +9,7 @@
   "types": "lib/index.d.ts",
   "scripts": {
     "build": "tsc",
+    "release": "np",
     "test": "jest",
     "test:coverage": "jest --coverage"
   },
@@ -36,6 +37,7 @@
   "devDependencies": {
     "@types/jest": "^26.0.22",
     "jest": "^26.6.3",
+    "np": "^7.5.0",
     "ts-jest": "^26.5.5",
     "typescript": "^4.2.4"
   }