Move node to >=12.14.1

Currently, OpenBMC uses node 12.14.1.
https://github.com/openbmc/openbmc/blob/master/meta-openembedded/meta-oe/recipes-devtools/nodejs/nodejs_12.14.1.bb
OpenBMC gets this recipe from meta-openembedded.

Moved the node required to ">=12.14.1" to allow this.

https://github.com/openbmc/webui-vue/commit/b346406f3aa407869a3c868fb14322fc529673a3
moved to node 12.16.x.

Without this change was seeing (when building an image with
webui-vue replacing phosphor-webui):
| > check-node-version --package && vue-cli-service build
|
| node: 12.14.1
| Wanted node version 12.16.x (>=12.16.0 <12.17.0)
| To install node, see https://nodejs.org/download/release/v12.16.0/
| npm ERR! code ELIFECYCLE
| npm ERR! errno 1
| npm ERR! webui-vue@0.1.0 build: `check-node-version --package && vue-cli-service build`
| npm ERR! Exit status 1
| npm ERR!
| npm ERR! Failed at the webui-vue@0.1.0 build script.

Tested: Built and loaded on a Witherspoon.
        No regressions observed.

Change-Id: I20fc81ccebc9a1eb37294e3966dc657836f08064
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/package.json b/package.json
index 5d0be2c..5482f54 100644
--- a/package.json
+++ b/package.json
@@ -53,7 +53,7 @@
     "vuepress": "1.4.0"
   },
   "engines": {
-    "node": "12.16.x"
+    "node": ">=12.14.1"
   },
   "gitHooks": {
     "pre-commit": "lint-staged"