Sorry to hear that.
For me it worked with those dependencies fixed.
pi@raspberrypi:~$ npm -v ; node -v
4.1.2
v7.7.1
pi@raspberrypi:~$ cd MagicMirror/
pi@raspberrypi:~/MagicMirror$ cd node_modules/
pi@raspberrypi:~/MagicMirror/node_modules$ npm install electron
> electron@1.6.6 postinstall /home/pi/MagicMirror/node_modules/electron
> node install.js
magicmirror@2.1.1 /home/pi/MagicMirror
└── electron@1.6.6
pi@raspberrypi:~/MagicMirror/node_modules$
Here the thread I’ve been looking last night: https://github.com/electron/electron/issues/9324
User: johannesjo made a fork: https://github.com/johannesjo/electron-prebuilt
But what I did was to downgrade the extract-zip:
pi@raspberrypi:~$ cd MagicMirror/
pi@raspberrypi:~/MagicMirror$ cd node_modules/
pi@raspberrypi:~/MagicMirror/node_modules$ npm uninstall extract-zip
.
.
.
pi@raspberrypi:~/MagicMirror/node_modules$ npm install extract-zip@1.6.0
.
.
.
pi@raspberrypi:~/MagicMirror/node_modules$ npm install electron
As a result of all this:
pi@raspberrypi:~/MagicMirror$ npm install
> magicmirror@2.1.1 install /home/pi/MagicMirror
> cd vendor && npm install
magicmirror-vendors@ /home/pi/MagicMirror/vendor
├── font-awesome@4.7.0
├── moment@2.18.1
├── moment-timezone@0.5.13
└── weathericons@2.1.0
> magicmirror@2.1.1 postinstall /home/pi/MagicMirror
> sh installers/postinstall/postinstall.sh
MagicMirror installation successful!
pi@raspberrypi:~/MagicMirror$
Hope it helps