[NEW] Wordpress auth (#1633)

README.md

android/app/src/main/res/drawable-hdpi/icon_wordpress.png

android/app/src/main/res/drawable-mdpi/icon_wordpress.png

android/app/src/main/res/drawable-xhdpi/icon_wordpress.png

android/app/src/main/res/drawable-xxhdpi/icon_wordpress.png

android/app/src/main/res/drawable-xxxhdpi/icon_wordpress.png

app/lib/rocketchat.js

app/views/LoginSignupView.js

...ages.xcassets/Icons/icon_wordpress.imageset/Contents.json

....xcassets/Icons/icon_wordpress.imageset/iconWordpress.png

...assets/Icons/icon_wordpress.imageset/iconWordpress@2x.png

...assets/Icons/icon_wordpress.imageset/iconWordpress@3x.png