fix install problem, node abi downlevel error

README.md

@@ -15,7 +15,7 @@ For example this can be used to send notifications to the following modules:
 Clone this repository in your `modules` folder, and install dependencies:
 ```bash
 cd ~/MagicMirror/modules # adapt directory if you are using a different one
-git clone https://github.com/Jopyth/MMM-Buttons.git
+git clone https://github.com/sdetweil/MMM-Buttons.git
 cd MMM-Buttons
 npm install # this can take a while
 ```

package.json

@@ -20,12 +20,9 @@
   },
   "homepage": "git+https://github.com/jopyth/MMM-Buttons#readme",
   "scripts": {
-    "postinstall": "node_modules/.bin/electron-rebuild -e ../../node_modules/electron"
+    "postinstall": "./postinstall"
   },
   "dependencies": {
     "onoff": "latest"
-  },
-  "devDependencies": {
-    "electron-rebuild": "^1.2.1"
   }
 }

postinstall

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+base=~/MagicMirror
+logfile=/dev/null
+if [ ! -e $base/node_modules/@electron/rebuild ];  then 
+    cd $base
+    if [ -e $base/node_modules/.bin/electron-rebuild ]; then 
+	# remove the old version	  
+      npm uninstall electron-rebuild >>$logfile 2>&1
+    fi	  
+    # install the new version 
+    npm install @electron/rebuild >>$logfile 2>&1
+    cd - >/dev/null
+fi
+
+
+$base/node_modules/.bin/electron-rebuild