Scheduling Envs (testbeds) for usage

Important: Keystack docker container must be running

- Go to the Envs page 
- Select 1 or more Envs to be scheduled for reserving and click at the top-bar link "Scheduler"
- Select the date and time to reserve the Env

- Options:
    - Select a date-and-time to automatically release the Env
          Note: If you don't set a release date-and-time, your scheduled reservation will automatically repeat
                at the scheduled date-and-time

    - Checkbox: Remove the scheduled reservation when the Env is reserved by the scheduler
          Note: This will automatically remove the scheduled reservation right after the env is reserved.
                If you don't checkbox this, your scheduled reservation will keep repeating the 
                scheduled reservation.

    - Select a user for the reservation


NOTE:
    Question: What if the env (testbed) is being used at the time when the Env is scheduled to be reserved?
    Answer: Your env reservation will go to the wait-list until the env is released

    Question: What will happen to all the scheduled reservations if the Keystack web-server is updated or rebooted?
    Answer: All scheduled reservations are kept in a persistant database.
            Keystack will restore all the scheduled reservations immediately upon a boot up

