replaced all clunky video encoding bits with JSAnimation library calls instead.  Beam Warming is still blowing up too fast
changed beamwarming to only use cfl=0.5 to avoid immediate blowups
removed video files made redundant by JSAnimation
reduced figsize of JSAnimations beccause the notebook file was >10mb and breaking nbviewer
fixed a few text formatting issues where the nbviewer rendering was breaking lines in an ugly way
removing ipython checkpoints from git
updated gitignore to ignore ipynb_checkpoints
Merge pull request #1 from barbagroup/jsanim

replacing videos in burgers notebook with JSAnimation animated plots