better handling of config type errors

[CamDavidsonPilon]

Ex: I had a comment beside the KF parameters,

[growth_rate_kalman]
acc_std=0.2
obs_std=3.0   # ↑ smooths growth rate
od_std=0.001
rate_std=2.5  # ↑ more responsive growth rate

but this isn't allowed in ini files, and when I call .getfloat, an error is thrown. However, the user just sees the job exit, with no error / warning. They need to run it from the command line to see the ValueError is thrown.