Fix URL in rtd-pip-requirements.txt
Adds to image.profile latitude and longitude profile from image functions
Adds unit tests for new functions for latitude and longitude profiles in gammapy.image
Require scipy>=0.14 in rtd-pip-requirements.txt
Merge pull request #167 from ellisowen/profiles

Profiles
Adds main catalog to image scripts to gammapy.image
Adds unit tests for newly added catalog to image scripts
Adds tutorial and supporting example scripts for new catalog to image methods
Updates tutorials index.rst file for newly added catalog to image tutorial
Makes small fix to units in flux column in populaltion.simulate to enable sphinx to build docs
Updates gammapy image __init__.py file for new image to catalog additions