fitobjective_api -> FlatDet

Tests/Py/Fit/fitobjective_api.py

@@ -27,7 +27,8 @@ class SimulationBuilder:
         sample.addLayer(ba.Layer(material))
 
         beam = ba.Beam(1., 1., 0)
-        detector = ba.SphericalDetector(self.m_ncol, 0, 1, self.m_nrow, 0, 1)
+        detector = ba.FlatDetector(self.m_ncol, self.m_nrow, 150, 150,
+                                   beam, ba.FlatDetector.X, 2000)
         simulation = ba.ScatteringSimulation(beam, sample, detector)
 
         return simulation