fix(common): CHECKOUT-3462 Remove Node engine field

Author: davidchin

package-lock.json

@@ -8,9 +8,6 @@
   "files": [
     "lib/"
   ],
-  "engines": {
-    "node": "^6.10.0"
-  },
   "repository": {
     "type": "git",
     "url": "git://github.com/bigcommerce/script-loader-js.git"
@@ -24,7 +21,7 @@
     "prebuild": "rm -rf lib",
     "build": "tsc --outDir lib --project tsconfig-build.json",
     "lint": "tslint 'src/**/*.ts' --config tslint.json --project tsconfig.json && tsc --noEmit",
-    "prepare": "npm run build",
+    "prepare": "check-node-version --node '>=6' --npm '>=6' && npm run build",
     "prerelease": "git fetch --tags && npm run validate-commits && npm run lint && npm test",
     "release": "standard-version",
     "postrelease": "npm publish --access public && git push --follow-tags",
@@ -41,6 +38,7 @@
     "@bigcommerce/tslint-config": "^2.0.1",
     "@bigcommerce/validate-commits": "^2.0.3",
     "@types/jest": "^21.1.10",
+    "check-node-version": "^3.2.0",
     "jest": "^21.2.1",
     "standard-version": "^4.2.0",
     "ts-jest": "^21.2.3",