image_stack_to_movie is broken

At one point, widgets were broken in jupytherhub, but now we are conda env associated with 2018-3. This function looks to be very broken at this point.
ValueError: Invalid file object: <_io.BufferedReader name=65> is the Exception, but I tried with just 10 images that were just a portion of the FastCCD image, so the problem is not with the input array.
Also not there are some requested enhancements for usability: https://github.com/NSLS-II-CSX/csxtools/issues/57
image_stack_to_movie(sub_images[0:10], vmin=np.percentile(sub_images[1],30), vmax=np.percentile(sub_images[1],90))  

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-193-d87213fc5ab6> in <module>()
      1 #THIS IS CURRENTLY BROKEN
      2 #
----> 3 image_stack_to_movie(sub_images[0:10], vmin=np.percentile(sub_images[1],30), vmax=np.percentile(sub_images[1],90))

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/site-packages/csxtools/ipynb/animation.py in image_stack_to_movie(images, frames, vmin, vmax, figsize, cmap, fps)
    102     plt.close(anim._fig)
    103     # return anim.to_html5_video()
--> 104     return HTML(_anim_to_html(anim, fps))
    105 
    106 

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/site-packages/csxtools/ipynb/animation.py in _anim_to_html(anim, fps)
    115             anim.save(f.name, fps=fps,
    116                       extra_args=['-vcodec', 'libx264',
--> 117                                   '-pix_fmt', 'yuv420p'])
    118             video = open(f.name, "rb").read()
    119         anim._encoded_video = base64.b64encode(video)

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/site-packages/matplotlib/animation.py in save(self, filename, writer, fps, dpi, codec, bitrate, extra_args, metadata, extra_anim, savefig_kwargs)
   1198                         # TODO: See if turning off blit is really necessary
   1199                         anim._draw_next_frame(d, blit=False)
-> 1200                     writer.grab_frame(**savefig_kwargs)
   1201 
   1202         # Reconnect signal for first draw if necessary

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/contextlib.py in __exit__(self, type, value, traceback)
     97                 value = type()
     98             try:
---> 99                 self.gen.throw(type, value, traceback)
    100             except StopIteration as exc:
    101                 # Suppress StopIteration *unless* it's the same exception that

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/site-packages/matplotlib/animation.py in saving(self, fig, outfile, dpi, *args, **kwargs)
    239             yield self
    240         finally:
--> 241             self.finish()
    242 
    243 

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/site-packages/matplotlib/animation.py in finish(self)
    365     def finish(self):
    366         '''Finish any processing for writing the movie.'''
--> 367         self.cleanup()
    368 
    369     def grab_frame(self, **savefig_kwargs):

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/site-packages/matplotlib/animation.py in cleanup(self)
    403     def cleanup(self):
    404         '''Clean-up and collect the process used to write the movie file.'''
--> 405         out, err = self._proc.communicate()
    406         self._frame_sink().close()
    407         _log.debug('MovieWriter -- Command stdout:\n%s', out)

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/subprocess.py in communicate(self, input, timeout)
    841 
    842             try:
--> 843                 stdout, stderr = self._communicate(input, endtime, timeout)
    844             finally:
    845                 self._communication_started = True

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/subprocess.py in _communicate(self, input, endtime, orig_timeout)
   1503                     selector.register(self.stdin, selectors.EVENT_WRITE)
   1504                 if self.stdout:
-> 1505                     selector.register(self.stdout, selectors.EVENT_READ)
   1506                 if self.stderr:
   1507                     selector.register(self.stderr, selectors.EVENT_READ)

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/selectors.py in register(self, fileobj, events, data)
    349 
    350         def register(self, fileobj, events, data=None):
--> 351             key = super().register(fileobj, events, data)
    352             poll_events = 0
    353             if events & EVENT_READ:

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/selectors.py in register(self, fileobj, events, data)
    235             raise ValueError("Invalid events: {!r}".format(events))
    236 
--> 237         key = SelectorKey(fileobj, self._fileobj_lookup(fileobj), events, data)
    238 
    239         if key.fd in self._fd_to_key:

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/selectors.py in _fileobj_lookup(self, fileobj)
    222         """
    223         try:
--> 224             return _fileobj_to_fd(fileobj)
    225         except ValueError:
    226             # Do an exhaustive search.

/opt/conda_envs/analysis-2018-2.1/lib/python3.6/selectors.py in _fileobj_to_fd(fileobj)
     37         except (AttributeError, TypeError, ValueError):
     38             raise ValueError("Invalid file object: "
---> 39                              "{!r}".format(fileobj)) from None
     40     if fd < 0:
     41         raise ValueError("Invalid file descriptor: {}".format(fd))

ValueError: Invalid file object: <_io.BufferedReader name=65>
NSLS-II-CSX / csxtools

image_stack_to_movie is broken #65
