Implements function to fetch fermi catalogs
Introduces a test for the Fermi fetch data function and makes a number of minor corrections to Fermi fetch data
Small changes to docstrings and relative import for test
Merge pull request #103 from ellisowen/fermi_catalog

Implements function to fetch fermi catalogs
Small docs update
Update Gaussian2DKernel argument from width to stddev
Update PoissonLikelihoodFitter to change in Astropy fitting code
Update .travis.yml to test Astropy development version
Remove unnecessary xfail from InverseComptonSpectrum test
Merge pull request #105 from cdeil/gaussian2d

Adapt Gammapy to recent Astropy API changes
Improve FermiPSF
Move PSF from morphology to irf sub-package
Add setup_package.py to gammapy/irf
Add fermi_model.xml
Move other PSF files from morphology to irf
Update setup_package.py files
Fix imports after moving morphology.psf to irf.psf
Rename PSF file names
Fix PSF imports after renaming
Improve morphology/gauss