Move linear problem example to examples folder.

SimPEG/Tests/test_basemesh.py

@@ -13,6 +13,7 @@ class TestBaseMesh(unittest.TestCase):
         self.assertTrue(self.mesh.dim, 3)
 
     def test_mesh_nc(self):
+        self.assertTrue(self.mesh.nC == 36)
         self.assertTrue(np.all(self.mesh.vnC == [6, 2, 3]))
 
     def test_mesh_nc_xyz(self):

SimPEG/Tests/test_example_linear.py

@@ -0,0 +1,13 @@
+import unittest
+import sys
+from SimPEG.Examples import Linear
+import numpy as np
+
+class TestLinear(unittest.TestCase):
+
+    def test_running(self):
+        Linear.run(100)
+        self.assertTrue(True)
+
+if __name__ == '__main__':
+    unittest.main()