Provide option to render more than one spinner at the same time

Suppose you get multiple long tasks at hand. It should be nice to be able to start more than one spinner before finishing the last one

take this as an example:

 from halo import Hal
 
 a = start_task_a()
 a_spinner = Halo({'text': 'Do A', 'spinner': 'dots'})
 a_spinner.start()
 a_is_spinning = True
 
 b = start_task_b()
 b_spinner = Halo({'text': 'Do B', 'spinner': 'dots'})
 b_spinner.start()
 b_is_spinning = True
 
 while a_is_spinning or b_is_spinning:
     if a.is_finished():
         a_spinner.succeed()
         a_is_spinning = False
     if b.is_finished():
         b_spinner.succeed()
         b_is_spinning = False

[bertokhoury]

@ManrajGrover maybe one simply needs to initialize that if two spinners are spinning. Then, simply print a new line betweem them?

[JustinTervala]

https://github.com/manrajgrover/halo/pull/155 looks like it would work for me.