Ensure a DiceExecutionError is raised when Dice fails

[caleb-johnson]

The current logic only raises a DiceExecutionError when subprocess.run fails to execute. This isn't the right logic since subprocess.run will successfully execute even if the underlying process returns a non-zero return code. This PR checks the returncode explicitly and raises a DiceExecutionError alerting users to the failure of the Dice command line application and pointing them to the logfile.