Updates load script for changes in FermiVelaRegion and adds load script fermi PSF for this region
Updates test script to accound for changes and additions in load script for FermiVelaRegion class
Updates load script to include cutout of fermi diffuse background model gll_iem_v05_rev1.fit for the vela region
Updates test script to test load of Fermi diffuse model
Merge pull request #162 from ellisowen/vela_region_changes

Vela region changes