v0.2.0

• New htmlwidgets for progressbar.js : see functions progress_line() and progress_circle().
• New functions show_modal_spinner() and remove_modal_spinner() to show a modal with a spinner and remove it.
• New functions show_modal_progress_line(), show_modal_progress_circle(), update_modal_progress() and remove_modal_progress() to show a modal with a progress bar, update it and remove it.
• New spinners available, see spin_epic() for a demo, or the online version : https://dreamrs.github.io/shinybusy/articles/spinners.html
• Two new vignettes are available : vignette("shinybusy-usage", package = "shinybusy") and vignette("spinners", package = "shinybusy").