Install all versions in .tool-versions with asdf
If you get the code for a new project and it is a project where versions are managed by asdf, then you will have a .tool-versions file and it will look something like this:
elixir 1.7.4-otp-21
erlang 21.3.8
If I don't have those versions installed, then generally I install those individually.
If your working directory is the same version as the .tool-versions file then you can install all versions specified in that file with:
asdf install