Fixes reference to redis-mpool
CDB-3686 Adds support for per mil tolerance when comparing images as in Mac OS X some results from ImageMagick are a bit odd
CDB-3657 Adds profiler as JSON to the header
Merge pull request #199 from CartoDB/CDB-3657

CDB-3657 Adds profiler as JSON to the header
Release 1.13.1
Stubs next version
Merge branch 'master' into CDB-3686