Not compatible with Nikola 8

[jamadden]

Specifically:

Traceback (most recent call last):
  File "//NIH/lib/python3.6/site-packages/doit/action.py", line 424, in execute
    returned_value = self.py_callable(*self.args, **kwargs)
  File "//NIH/lib/python3.6/site-packages/nikola/nikola.py", line 1390, in render_template
    template_name, None, local_context)
  File "//src/nti/nikola_chameleon/plugin.py", line 194, in render_template
    result = self.render_template_to_string(template_name, context)
  File "//src/nti/nikola_chameleon/plugin.py", line 232, in render_template_to_string
    if post.is_mathjax:
AttributeError: 'Post' object has no attribute 'is_mathjax'

Here's a document about new things in nikola 8 and here's a document about upgrading

I'm not sure there's an advantage to continuing to support nikola 7 (other than python 2.7 support).