Update setup.py

setup.py

@@ -22,7 +22,7 @@ setup(name='AmpScan',
       author_email='Joshua.Steer@soton.ac.uk',
       license='MIT',
       packages=['AmpScan',],
-      install_requires=['numpy', 'pandas', 'matplotlib', 'scipy', 'sphinxcontrib-napoleon'],
+      install_requires=['numpy', 'pandas', 'matplotlib', 'scipy', 'sphinxcontrib-napoleon', 'vtk'],
       package_data={'example_stl':' 01_PhantomShell_ICEM_3mm.stl'},
       include_package_data=True,
       zip_safe=False)