chore(grunt): update imagemin-task

-- update dependency from 0.5.0 to 0.7.0
-- include all files for imagemin instead only folders
chore(grunt): update browser-sync

-- update from 0.5.7 to 0.9.1
-- rename browser_sync to browserSync
refactor(grunt): rename task "server" to "server"

-- use "grunt server" for running the process
refactor(*): same folder-structure in build & dist like in the development-process

-- generating html in /views
Merge pull request #1 from timhartmann/develop

Develop