Implement AdMob advertising to generate revenue in all fragments

[lschmid83]

I would like to implement a small advertising banner displayed at the bottom of every fragment in the app which updates when the user selects a tab. It could also be possible to display a full screen advert at random intervals based on how long the user has spent using the app. If this was implemented there will be a subscription system for say £20 a year which removes all advertisements from the app for subscribers or potentially a monthly subscription for say £2.50 to access the meeting finder map and additional app features similiar to the PinkCloud meeting finder app avaiable.