Merge pull request #463 from kosack/master

ctapipe/image/muon/muon_diagnostic_plots.py

ctapipe/image/tests/test_charge_extraction.py

ctapipe/instrument/__init__.py

ctapipe/instrument/camera.py

ctapipe/instrument/subarray.py

ctapipe/instrument/telescope.py

ctapipe/plotting/camera.py

ctapipe/plotting/event_viewer.py

ctapipe/plotting/tests/test_array.py

ctapipe/plotting/tests/test_camera.py

ctapipe/reco/HillasReconstructor.py

ctapipe/tools/dump_instrument.py

examples/display_summed_images.py