Add mixed[] to phpdocs for workload (php-task#42)

* Add string[] to phpdocs for workload

* change string[] to mixed[]

Create .gitattributes (php-task#41)

Less files for installed composer package

updated symfony components (php-task#40)

bumped version number

removed hhvm from travis config

prepared 1.0.0 tag

updated changelog

updated changelog

fixed return of task-builder cron

prepared version tag