vendor/cache to gitignore
fix #780 - add nickname and links to emails and transaction views
Restructure statistics and add article/transaction statistics by category - fixes #784
Merge branch 'develop' of github.com:fairnopoly/fairnopoly into develop
fix a few test suite issues
Merge branch 'feature-category-sales-statistics' into develop
remove whitespace for rbp
fix #781 - delete library_elements when article is sold out and prevent collection on sold_out articles
statistics reworked
Merge branch 'develop' into feature-category-sales-statistics
statistic rework added files
trailing whitespace
Merge branch 'develop' of github.com:fairnopoly/fairnopoly into develop