Failing to build the docs

[arokem]

When running a make html, I currently get the following exception:

Exception occurred:
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/subprocess.py", line 1344, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'jsdoc': 'jsdoc'

This is after installing numpydoc and sphinx_js (following the error described in #268)

[richford]

Resolved in 403d51a of #268.