#820 revert scikit fem version and add citation

Author: valentinsulzer

.requirements-docs.txt

@@ -1,11 +1,10 @@
 # Requirements for readthedocs.io
 numpy>=1.14
-scipy>=1.0
+scipy>=1.3
 pandas>=0.23
 anytree>=2.4.3
 autograd>=1.2
 scikit-fem>=0.2.0
 casadi>=3.5.0
 guzzle-sphinx-theme
 sphinx>=1.5
-python-Levenshtein>=0.12.0

pybamm/CITATIONS.txt

@@ -123,3 +123,15 @@ journal={ECSarXiv. February},
 volume={7},
 year={2020}
 }
+
+@software{scikit-fem,
+  author       = {Tom Gustafsson and
+                  Geordie McBain},
+  title        = {kinnala/scikit-fem 0.4.0},
+  month        = jan,
+  year         = 2020,
+  publisher    = {Zenodo},
+  version      = {0.4.0},
+  doi          = {10.5281/zenodo.3597656},
+  url          = {https://doi.org/10.5281/zenodo.3597656}
+}

pybamm/spatial_methods/scikit_finite_element.py

@@ -29,6 +29,7 @@ class ScikitFiniteElement(pybamm.SpatialMethod):
 
     def __init__(self, options=None):
         super().__init__(options)
+        pybamm.citations.register("scikit-fem")
 
     def build(self, mesh):
         super().build(mesh)

tests/integration/test_models/test_full_battery_models/test_lithium_ion/test_dfn.py

@@ -34,6 +34,7 @@ def test_basic_processing_1plus1D(self):
         modeltest.test_all(skip_output_tests=True)
 
     def test_basic_processing_2plus1D(self):
+        pybamm.set_logging_level("DEBUG")
         options = {"current collector": "potential pair", "dimensionality": 2}
         model = pybamm.lithium_ion.DFN(options)
         var = pybamm.standard_spatial_vars
@@ -48,6 +49,7 @@ def test_basic_processing_2plus1D(self):
         }
         modeltest = tests.StandardModelTest(model, var_pts=var_pts)
         modeltest.test_all(skip_output_tests=True)
+        pybamm.set_logging_level("WARNING")
 
     def test_optimisations(self):
         options = {"thermal": "isothermal"}

tests/unit/test_citations.py

@@ -74,6 +74,14 @@ def test_sulzer_2019(self):
         pybamm.lead_acid.Full(build=False)
         self.assertIn("sulzer2019physical", citations._papers_to_cite)
 
+    def test_scikit_fem(self):
+        citations = pybamm.citations
+
+        citations._reset()
+        self.assertNotIn("scikit-fem", citations._papers_to_cite)
+        pybamm.ScikitFiniteElement()
+        self.assertIn("scikit-fem", citations._papers_to_cite)
+
     def test_parameter_citations(self):
         citations = pybamm.citations