Update Middleman to version 3.3.9
Update Middleman to version 3.3.9

claylo/api-docs,bookiza/docs,linchpinio/docs,claylo/api-docs,bookiza/docs,Ibercheck/api-docs,bookiza/docs,bookiza/docs,Ibercheck/api-docs,linchpinio/docs,linchpinio/docs,claylo/api-docs,kasko/docs,Ibercheck/api-docs