UnhandledPromiseRejectionWarning: SyntaxError: Unexpected token < in JSON at postion 83

**Description:**
Unable to install cordova plugin.

**Steps to Reproduce:**
running the following command in my terminal: `ionic cordova plugin add cordova-plugin-google-analytics`

**Output:**
```
> cordova plugin add cordova-plugin-google-analytics --save
(node:3095) UnhandledPromiseRejectionWarning: SyntaxError: Unexpected token < in JSON at position 83
at JSON.parse ()
at getJson (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/plugman/util/metadata.js:29:31)
at Object.exports.save_fetch_metadata (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/plugman/util/metadata.js:56:24)
at /usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/plugman/fetch.js:203:18
at _fulfilled (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/q/q.js:787:54)
at self.promiseDispatch.done (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/q/q.js:816:30)
at Promise.promise.promiseDispatch (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/q/q.js:749:13)
at /usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/q/q.js:509:49
at flush (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/q/q.js:108:17)
at _combinedTickCallback (internal/process/next_tick.js:131:7)
(node:3095) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:3095) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

```

**My `ionic info`:**

```
cli packages: (/usr/local/lib/node_modules)

@ionic/cli-utils : 1.19.2
ionic (Ionic CLI) : 3.20.0

global packages:

cordova (Cordova CLI) : 8.0.0

local packages:

@ionic/app-scripts : 3.1.7-201801172029
Cordova Platforms : android 7.0.0 ios 4.5.4
Ionic Framework : ionic-angular 3.9.1-201711081842

System:

Android SDK Tools : 26.1.1
ios-deploy : 1.9.2
Node : v8.11.1
npm : 5.6.0
OS : macOS High Sierra
Xcode : Xcode 9.2 Build version 9C40b

Environment Variables:

ANDROID_HOME : /Users/gcvanrooyen25gmail.com/Library/Android/sdk

Misc:

backend : pro
```

**Other Information:**
**package Json**
```
{
"name": "sidemenu_ionic",
"version": "0.0.1",
"author": "Ionic Framework",
"homepage": "http://ionicframework.com/",
"private": true,
"config": {
"ionic_webpack": "./webpack.config.js"
},
"scripts": {
"clean": "ionic-app-scripts clean",
"start": "concurrently \"ionic-app-scripts serve --dev\" \"NODE_ENV=dev nodemon server.js\" ",
"builduat": "concurrently \"ionic-app-scripts build --dev\" \"NODE_ENV=dev nodemon server.js\" ",
"build": "ionic-app-scripts build --prod",
"lint": "ionic-app-scripts lint",
"ionic:build": "ionic-app-scripts build --prod",
"ionic:serve": "ionic-app-scripts serve",
"prod": "concurrently \"ionic-app-scripts serve --prod\" \"NODE_ENV=prod node initialize_admin.js\" ",
"server": " NODE_ENV='dev' nodemon ./server.js "
},
"dependencies": {
"@angular/common": "^5.2.1",
"@angular/compiler": "5.2.1",
"@angular/compiler-cli": "5.2.1",
"@angular/core": "5.2.1",
"@angular/forms": "5.2.1",
"@angular/http": "5.2.1",
"@angular/platform-browser": "5.2.1",
"@angular/platform-browser-dynamic": "5.2.1",
"@ionic-native/core": "4.4.0",
"@ionic-native/google-analytics": "^4.7.0",
"@ionic-native/splash-screen": "4.4.0",
"@ionic-native/status-bar": "4.4.0",
"@ionic/pro": "1.0.16",
"@ionic/storage": "2.1.3",
"aws-sdk": "^2.200.0",
"body-parser": "^1.18.2",
"concurrently": "^3.5.1",
"cordova-plugin-google-analytics": "^1.8.3",
"defaultable": "^0.7.2",
"dns": "^0.2.2",
"express": "^4.16.2",
"firebase": "^4.8.0",
"firebase-admin": "^5.11.0",
"firebase-functions": "^0.9.1",
"heroku-ssl-redirect": "0.0.4",
"ionic-angular": "nightly",
"ionicons": "3.0.0",
"nodemailer": "^4.4.2",
"nodemailer-ses-transport": "^1.5.1",
"process": "^0.11.10",
"pug": "^2.0.1",
"rxjs": "5.5.2",
"sendpulse-api": "^1.0.3",
"shortid": "^2.2.8",
"sw-toolbox": "3.6.0",
"swig": "^1.4.2",
"swig-email-templates": "^5.0.1",
"zone.js": "0.8.18"
},
"devDependencies": {
"@ionic/app-scripts": "nightly",
"chokidar": "^2.0.3",
"nodemon": "^1.14.11",
"rollup-plugin-replace": "^2.0.0",
"typescript": "2.4.2"
},
"description": "An Ionic project",
"cordova": {
"plugins": {
"cordova-plugin-google-analytics": {}
}
}
}
```