Error: Failed to fetch plugin from a URL

**Description:**
ionic cordova plugin add {URL} fails.
I tried to add the WKWebView as an example on a brand new ionic app, and it failed.
ionic cordova plugin add https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git --save

However, if I run the command without the "ionic" (i.e. using Cordova) it works fine. However, when packaging in the Ionic Cloud, it doesn't seem to work.

cordova plugin add https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git --save

**Steps to Reproduce:**
Create a new Ionic Blank App
Run: ionic cordova plugin add https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git --save

**Output:**
C:\mobile\TestApp>ionic cordova plugin add https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git --save
> cordova plugin add https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git --save
× Running command - failed!
[ERROR] An error occurred while running cordova plugin add

https://github.com/ionic-team/cordova-plugin-wkwebview-engine... (exit code 1):

Error: Failed to fetch plugin https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git via registry.
Probably this is either a connection problem, or plugin spec is incorrect.
Check your connection and plugin name/version/URL.
Error: cmd: Command failed with exit code 1 Error output:
npm WARN addRemoteGit Error: Command failed: git -c core.longpaths=true config --get remote.origin.url
npm WARN addRemoteGit
npm WARN addRemoteGit at ChildProcess.exithandler (child_process.js:204:12)
npm WARN addRemoteGit at emitTwo (events.js:106:13)
npm WARN addRemoteGit at ChildProcess.emit (events.js:191:7)
npm WARN addRemoteGit at maybeClose (internal/child_process.js:886:16)
npm WARN addRemoteGit at Socket. (internal/child_process.js:342:11)
npm WARN addRemoteGit at emitOne (events.js:96:13)
npm WARN addRemoteGit at Socket.emit (events.js:188:7)
npm WARN addRemoteGit at Pipe._handle.close [as _onclose] (net.js:497:12)
npm WARN addRemoteGit git+https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git resetting remote
C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\git-https-github-com-ionic-team-cordova-plugin-wkwebview-engine-git-ae2e0322
because of error: { Error: Command failed: git -c core.longpaths=true config --get remote.origin.url
npm WARN addRemoteGit
npm WARN addRemoteGit at ChildProcess.exithandler (child_process.js:204:12)
npm WARN addRemoteGit at emitTwo (events.js:106:13)
npm WARN addRemoteGit at ChildProcess.emit (events.js:191:7)
npm WARN addRemoteGit at maybeClose (internal/child_process.js:886:16)
npm WARN addRemoteGit at Socket. (internal/child_process.js:342:11)
npm WARN addRemoteGit at emitOne (events.js:96:13)
npm WARN addRemoteGit at Socket.emit (events.js:188:7)
npm WARN addRemoteGit at Pipe._handle.close [as _onclose] (net.js:497:12)
npm WARN addRemoteGit killed: false,
npm WARN addRemoteGit code: 1,
npm WARN addRemoteGit signal: null,
npm WARN addRemoteGit cmd: 'git -c core.longpaths=true config --get remote.origin.url' }
npm ERR! git clone --template=C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\_templates --mirror
https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git
C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\git-https-github-com-ionic-team-cordova-plugin-wkwebview-engine-git-ae2e0322:
Cloning into bare repository
'C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\git-https-github-com-ionic-team-cordova-plugin-wkwebview-engine-git-ae2e0322'...
npm ERR! git clone --template=C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\_templates --mirror
https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git
C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\git-https-github-com-ionic-team-cordova-plugin-wkwebview-engine-git-ae2e0322:
fatal: Unable to find remote helper for 'https'
npm ERR! Windows_NT 10.0.14393
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program
Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install"
"https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git" "--save"
npm ERR! node v6.10.3
npm ERR! npm v3.10.10
npm ERR! code 128

npm ERR! Command failed: git -c core.longpaths=true clone
--template=C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\_templates --mirror
https://github.com/ionic-team/cordova-plugin-wkwebview-engine.git
C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\git-https-github-com-ionic-team-cordova-plugin-wkwebview-engine-git-ae2e0322
npm ERR! Cloning into bare repository
'C:\Users\user\AppData\Roaming\npm-cache\_git-remotes\git-https-github-com-ionic-team-cordova-plugin-wkwebview-engine-git-ae2e0322'...
npm ERR! fatal: Unable to find remote helper for 'https'
npm ERR!
npm ERR!
npm ERR! If you need help, you may report this error at:
npm ERR!

npm ERR! Please include the following file with any support request:
npm ERR! C:\mobile\TestApp\node_modules\npm-debug.log

**My `ionic info`:**

cli packages: (C:\mobile\TestApp\node_modules)

@ionic/cli-utils : 1.9.2
ionic (Ionic CLI) : 3.9.2

global packages:

Cordova CLI : 7.0.1

local packages:

@ionic/app-scripts : 2.1.4
Cordova Platforms : android 6.2.3 browser 4.1.0 ios 4.4.0
Ionic Framework : ionic-angular 3.6.0

System:

Node : v6.10.3
npm : 3.10.10
OS : Windows 10

**Other Information:**