Merge pull request #67 from liuggio/master

adding (some) authors, and improved image creator
redis cache api response
Merge pull request #68 from liuggio/api_cache

[WIP] Api Cached
Added Imagine dependency and created configuration
for dependency injection.
ImageCreator service refactored: removed all references to gd direct calls
Trying to fix vertical text position across libraries
Refactored text vertical drawing
Minor configuration refactor for key imagine_driver
Merge pull request #69 from stewe/switch-to-imagine

Switch calls from gd to Imagine library
Update .travis.yml
added better version_comparison
CS and minor fixes
improved comparison