Improve Action Error Messages

[TheCedarPrince]

Is your feature request related to a problem? Please explain.

It can be difficult to track where an error is being thrown from the javis function when multiple actions are being tied together. Currently, if there is an error in javis the error handler says that there is an error within javis but not why it is being caused.

Describe the solution you'd like

It would be nice if I could have a traceback such that I can locate the specific Action that caused an error and perhaps even what part of the Action failed. Going deeper, after locating the Action, perhaps even the SubAction as well.

Describe alternatives you've considered

Commenting can work, but only so much. I'd rather have an intelligent and intelligible error message that can tell me why I am screwing up.

[Wikunia]

I think implementing #100 will make this obsolete.
Then we would define actions outside the javis function and go the way that JuMP.jl is doing