Fix/pipeline

@osander: rod3d does not build if DUNE_VTK is installed, this was the reason for the pipeline to fail.

src/CMakeLists.txt

 set(programs compute-disc-error
              cosserat-continuum
              gradient-flow
-             harmonicmaps)
+             harmonicmaps
+             rod3d)
 #            rodobstacle)
 
-if (NOT dune-vtk_FOUND)
-  set(programs rod3d ${programs})
-endif()
-
 if (${DUNE_ELASTICITY_VERSION} VERSION_GREATER_EQUAL 2.8)
   set(programs film-on-substrate-stress-plot ${programs})
 endif()