Merge pull request ethjs#4 from legobeat/deprecate-nodev6

deprecate nodejs < v8.17, npm < v6

Author: legobeat

docs/developer-guide.md

@@ -75,8 +75,8 @@ After build staging it is the `lib` folder which actually gets published to NPM.
 ## NPM/Node Version Requirements
 
 `ethjs` requires you have:
-  - `nodejs` -v 6.5.0+
-  - `npm` -v 3.0+
+  - `nodejs` -v 8.17.0+
+  - `npm` -v 6.0+
 
 This is a requirement to run, test, lint and build this module.
 

package.json

@@ -132,8 +132,8 @@
     "webpack": "2.1.0-beta.15"
   },
   "engines": {
-    "node": ">=6.5.0",
-    "npm": ">=3"
+    "node": ">=8.17.0",
+    "npm": ">=6"
   },
   "eslintConfig": {
     "parser": "babel-eslint",
@@ -209,7 +209,7 @@
     "lint:js": "npm run lint:eslint -- . ",
     "lint:staged": "lint-staged",
     "prebuild": "npm run build:clean && npm run test",
-    "prepublish": "npm run build",
+    "prepare": "npm run build",
     "pretest": "npm run lint",
     "release": "npmpub",
     "start": "npm test",