Uncomment checksum assert in IRF tests
Adds to gammapy.datasets scripts to load fermi extended source catalog images
Adds fermi extended sources test case
Merge pull request #152 from ellisowen/extended_sources

Extended sources
Adds FermiVelaRegion load scripts to datasets
Adds unit test for Fermi Vela Region
Adds supporting changes in setup_package.py for new FermiVelaRegion class
Merge pull request #156 from ellisowen/fermi_source_data

Fermi source data
Merge branch 'master' of https://github.com/gammapy/gammapy into npred_cube2
updates plotting scripts