Release v3.1.0 (#173)

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

package.json

@@ -8,13 +8,13 @@
   "copyright": "© 2020, Lakend Labs, Inc.",
   "license": "MIT",
   "description": "The Kubernetes IDE",
-  "version": "3.1.0-rc.1",
+  "version": "3.1.0",
   "main": "main.ts",
   "config": {
     "bundledKubectlVersion": "1.17.3"
   },
   "engines": {
-    "node": ">=0.12 <0.13"
+    "node": ">=12.0 <13.0"
   },
   "build": {
     "afterSign": "build/notarize.js",