disable phasefield tests on Sympy 1.1

conftest.py

@@ -52,6 +52,12 @@ except ImportError:
     collect_ignore += [os.path.join(SCRIPT_FOLDER, "lbmpy_tests/benchmark"),
                        os.path.join(SCRIPT_FOLDER, "lbmpy_tests/full_scenarios/kida_vortex_flow/scenario_kida_vortex_flow.py")]
 
+import sympy
+sver = sympy.__version__.split(".")
+if (int(sver[0]) == 1 and int(sver[1]) < 2):
+    add_path_to_ignore('lbmpy_tests/phasefield')
+    collect_ignore += [os.path.join(SCRIPT_FOLDER, "lbmpy_tests/test_n_phase_boyer_noncoupled.ipynb")]
+
 collect_ignore += [os.path.join(SCRIPT_FOLDER, 'setup.py')]
 
 for root, sub_dirs, files in os.walk('.'):