Add more badges to README
Add LONG_DESCRIPTION.rst
Read LONG_DESCRIPTION from LONG_DESCRIPTION.rst in setup.py
Merge pull request #190 from cdeil/badges_and_description

Status shields and LONG_DESCRIPTION
Updates the Index RST file with slightly new gammapy background value
Updates plotting scripts for npred cube
Updates plots in npred tutorial
Changes to mirror convolution for edged in spectral_cube, npred
Merge pull request #189 from ellisowen/npred_plots

Uses Aplpy FITSFigure in Npred plots
Adds Fermi-LAT PSF data files
Adds loads script for PSF files
Adds unit tests for loading of PSF files