Error when `mdv README.md`

[michael135]

I've tried to mdv README.md and got the following error:

/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py:1276: YAMLLoadWarning: calling yaml.load() without Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.
  cfg = yaml.load('{}')
Traceback (most recent call last):
  File "/home/michaeld/.local/bin/mdv", line 11, in <module>
    load_entry_point('mdv==1.6.3', 'console_scripts', 'mdv')()
  File "/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py", line 1353, in run
    print(run_args(args))
  File "/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py", line 1309, in run_args
    tab_length    = args.get('-b', 4))
  File "/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py", line 1063, in main
    the_html = MD.convert(md)
  File "/home/michaeld/.local/lib/python3.6/site-packages/markdown/core.py", line 268, in convert
    newRoot = treeprocessor.run(root)
  File "/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py", line 873, in run
    formatter(doc, out)
  File "/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py", line 868, in formatter
    formatter(c, out, hir + 1, parent=el)
  File "/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py", line 868, in formatter
    formatter(c, out, hir + 1, parent=el)
  File "/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py", line 690, in formatter
    links_list, t = replace_links(el, t)
  File "/home/michaeld/.local/lib/python3.6/site-packages/mdv/markdownviewer.py", line 624, in replace_links
    cur += '%s ' % unichr(link_start_ord + cur_link)
NameError: name 'unichr' is not defined