Directories "cosmo_db" and "cosmo_output" are not automatically created if they don't exist

[lmiller20]

In order for COSMO to function normally, it requires the user to define environment variables with the location of two directories, "cosmo_db" and "cosmo_output". However, these directories are not automatically created by the install if they don't already exist on the user's computer, and we do not give instructions to make them otherwise. As such, the environment variables will point to directories that don't exist, and the user may not realize they need create them on their own.