Customize the command used to install CocoaPods

From @NathanWalker on March 19, 2016 23:55

Because some CocoaPods can be finicky at best to get working with {N} plugins, it would probably help to be able to customize or specify a command to run a pod install.
For example, please see this issue:
https://github.com/segment-integrations/analytics-ios-integration-google-analytics/issues/3#issuecomment-164874798

The issue arises from the Segment-GoogleAnalytics pod and the solution posted above involves a custom install of CocoaPods and the usage of bundle exec pod install along with a Gemfile to circumvent the issues.

It would be nice that when running tns emulate ios with CocoaPods involved, a command line argument could be passed to provide a custom pod install command to be able to use this solution.

Working on this {N} plugin for Segment:
https://github.com/NathanWalker/nativescript-segment
Blocked by this at moment.

Copied from original issue: NativeScript/ios-runtime#535

Beginne beim Ablauf tns emulate ios und verfolge, wo CocoaPods pod install ausführt. Prüfe den angeforderten Workaround mit bundle exec pod install und Gemfile und definiere anschließend, wie ein benutzerdefinierter Befehl bereitgestellt würde. Als abgeschlossen gilt die Aufgabe, wenn der iOS-Emulationsablauf diesen Befehl für Projekte verwenden kann, die eine angepasste CocoaPods-Installation benötigen.