Fix location of progress_bar

[Leonid Isaev]

I think in ampy/cli.py, progress_bar should be namespaced, i.e.

ampy/cli.py:
...
    31	from progress_bar import PorgressBar
    32	from progress_bar import PorgressBarBath
...

should be

ampy/cli.py:
...
    31	from ampy.progress_bar import PorgressBar
    32	from ampy.progress_bar import PorgressBarBath
...

similar to files and pyboard.

Thanks!