Check behaviour of Everytime/Anytime scripts, and one-time scripts, wrt and hashing

[erikbra]

Ref https://github.com/chucknorris/roundhouse/issues/424

• What does grate do if an Anytime/Everytime script is changed, and re-run?
• What does grate do if we change a one-time script, and we run with --warnononetimescriptchanges
• On the next run, make sure we use the latest run of the script to compare the hash, not a random one.