docs: stop using mock to allow solve_fe docs

The solve_fe function can now be imported without sfepy being required
so remove all the mock paraphernalia from conf.py.

doc/conf.py

@@ -28,36 +28,6 @@
 copyright = u'2021, Daniel Wheeler'
 
 
-MOCK_MODULES = [
-    'sfe',
-    'sfepy',
-    'sfepy.base',
-    'sfepy.discrete',
-    'sfepy.discrete.fem',
-    'sfepy.discrete.conditions',
-    'sfepy.terms',
-    'sfepy.solvers',
-    'sfepy.solvers.ls',
-    'sfepy.solvers.nls',
-    'sfepy.discrete.fem.periodic',
-    'sfepy.mesh',
-    'sfepy.mesh.mesh_generators',
-    'sfepy.mechanics',
-    'sfepy.mechanics.matcoefs',
-    'sfepy.base.base'
-]
-
-import mock
-
-for module in MOCK_MODULES:
-    sys.modules[module] = mock.Mock()
-
-m = mock.MagicMock()
-d = dict(key='value')
-m.__getitem__.side_effect = d.__getitem__
-sys.modules['sfepy.base.goptions'] = m
-
-
 import pymks
 version = pymks.__version__
 release = pymks.__version__

doc/requirements.txt

@@ -1,12 +1,10 @@
 sphinx
-sphinx_bootstrap_theme
 pytest
 numpy
 toolz
 dask
 matplotlib
 scikit-learn
-mock
 nbsphinx==0.5.1
 m2r2
 Deprecated