Merge pull request #2723 from miykael/remove_matplotlib_sphinx_extension

FIX: corrects readthedocs build error

Author: effigies

doc/conf.py

@@ -50,7 +50,7 @@
               'sphinx.ext.autosummary',
               'numpydoc',
               'matplotlib.sphinxext.plot_directive',
-              'matplotlib.sphinxext.only_directives',
+              #'matplotlib.sphinxext.only_directives',
               'nipype.sphinxext.plot_workflow',
               #'IPython.sphinxext.ipython_directive',
               #'IPython.sphinxext.ipython_console_highlighting'