adokter/bioRad: bioRad 0.4.0

First release on CRAN! All issues included in this release can be found here. get_param() added as new function to get parameters from scan (#132). download_basemap() now uses Stamen basemaps by default (parameter source), so users do not need to request an API key for the previous default Google Maps (#163). download_vpfiles() and select_vpfiles() now use 5 letter radar codes (parameter radars instead of radar and country), allow to skip already downloaded files (parameter overwrite = TRUE) and have improved download and error messages (#176). read_pvolfile(), nexrad_to_odim() and calculate_vp() (all Docker dependent) can now read files from directories containing a space (#162). Details for deprecated functions mt(), mtr(), cmt() are now displayed with function (#166). README reviewed for easier installation and usage (#155). Get started vignette is now based on figure and workflow from Dokter et al. (#168). Introductory exercises vignette renamed to rad_aero_18.Rmd since it is based on the 2nd Radar Aeroecology Training School. bioRad now has a code of conduct and contributing guidelines (#145). Full changelog: https://adokter.github.io/bioRad/news/index.htm