Removed blob detection
Merge pull request #192 from adonath/remove_blob_detect

Removed blob detection
Add linkchecker to travis-ci sphinx build
Merge pull request #193 from cdeil/linkchecker

Add linkchecker to travis-ci sphinx build
Fix Sphinx broken link
Update astropy_helpers sub-module pointer to latest master
Merge pull request #196 from cdeil/ah-update

Update astropy_helpers sub-module pointer to latest master
Adds iterative background kernel estimation code to gammapy.background
Adds unit tests for new iterative background kernel estimation code
Updates background init.py file to include background estimation code
Adds background iteratative estimation tutorial RST file
Adds tutorial plotting script
Updates tutorials index.rst file to include new background tutorial
Bug fixes in background kernel script