spread 2019.8.5

Submitted to CRAN.

Exported functions:

• commuter
• convert_blank_seiiar_with_vax

Exported datasets:

• norway_commuters_2017
• norway_seiiar_noinfected_2017
• norway_seiiar_oslo_2017
• norway_seiiar_measles_noinfected_2017
• norway_seiiar_measles_oslo_2017