Delete gammapy-image-crab.ipynb
Delete gammapy-image-crab.ipynb

This file was added to gammapy-extra by @kingj90 and we'll maintain it there.
gammapy/PyGamma15,gammapy/PyGamma15,gammapy/PyGamma15,gammapy/2015-MPIK-Workshop,gammapy/2015-MPIK-Workshop,gammapy/2015-MPIK-Workshop