PA Review: Bookings

Functionality

[x] Can view booking form on each spot show page
[x] Can book spot if signed in
[x] User is asked to sign in when booking spot if they have not already
[x] Upon booking spot, signed in user is redirected to trips page (booking index)
[x] Signed in user can view all booking by clicking the trips tab in the nav bar
[x] User can cancel booking on the booking index page.
[x] User can update booking by clicking on the update booking button on the booking index page and filling in the edit booking form page that the user is redirected to