[Feature] appInvite isn't supported anymore, remove feature

[peterpeterparker]

I'm submitting a ... (check one with "x")
[ X] a remove feature request

Current behavior:
appInvite code is still present in the plugin

Expected behavior:
appInvite has been mark as deprecated in November 2017 and ended February 5, 2018. Therefore the features of this plugin should/could be removed

Sources:

https://stackoverflow.com/questions/47196972/facebook-app-invites-is-deprecated

https://blog.getsocial.im/facebook-deprecates-app-invites-are-you-ready/

Facebook official announcement

November 16, 2017: https://developers.facebook.com/blog/post/2017/11/07/changes-developer-offerings/

Report

Code removed in the master branch. I have then installed the plugin, removing/adding platform, building and finally tested that the login was still ok, which was the case

Ionic native

PR submitted to reflect this change with danielsogl/awesome-cordova-plugins#2469