Use package files instead of npmignore

.npmignore

@@ -1,13 +0,0 @@
-.cproject
-.idea
-.lock-wscript
-.DS_Store
-.project
-.DS_Store
-.eslintrc
-.gitignore
-node_modules/
-package-lock.json
-test/
-examples/
-*.log

package.json

@@ -17,6 +17,17 @@
 		"napi",
 		"gyp"
 	],
+	"files": [
+		"bat",
+		"include",
+		"download.js",
+		"index.js",
+		"install.js",
+		"writable-buffer.js",
+		"LICENSE",
+		"package.json",
+		"README.md"
+	],
 	"engines": {
 		"node": ">=10.16.1",
 		"npm": ">=6.9.0"

test/package.json

@@ -5,7 +5,7 @@
 	"main": "mocha",
 	"scripts": {
 		"test": "mocha",
-		"preinstall": "cd .. && npm ci"
+		"postinstall": "cd .. && npm ci"
 	},
 	"dependencies": {
 		"chai": "4.2.0",