kwb.qmra 0.3.0

Adaptions for project Smart-Control:

• Added stats summary outputs to risk output list (i.e. stats_total and
  stats_logreductions)

• Added wrapper functions for OpenCPU (kwb.qmra::opencpu_config_read,
  kwb.qmra::opencpu_simulate_risk) and example JSON datasets based on dummy config
  (config_json and `risk_json)

• Fixes: fix deprecation warning for dplyr::tbl_df() by replacing with
  dplyr::as_tibble()

• Continuous integration: moved to github-actions (instead of travis-ci and
  appveyor)