SE: Version control for swell_static_files

[ashiklom]

From @Dooruk on #360 (#360 (comment))

This is a separate concern but during the SWELL development meeting there was a brief discussion on version control with the swell_static_files. Sounds like there is no straightforward solution to that since it requires handling many different large file formats. My suggestion for now is that we can name the static files as the SWELL version and keep the previous static folders up to 4-5 most recent versions.