Allow for providing the password at runtime

Not perfect, but allows for an alternative method to provide the TMSS password other than fixed in the yaml file.

getpass is a standard library module for handling passwords: https://docs.python.org/3/library/getpass.html to handle clearing inputs while typing, but does not provide safety against any MITM/stdin capture, or encrypt the password while it is in memory, but at least it's not just sitting around on disk.