fix: allow CSV read exception to propagate instead of catching it

[ToddFincannon]

Removed the try/catch block as agreed.

This is an additional fix for #81 as discussed in PR #82; will be merged into the todd/81-direct-data-csv branch.

Chris edit: I'm pasting the additional context from Todd's comment from #82:

I removed the try/catch block around the CSV parse. I tested it with a bad pathname and got the following unhandled exception error message:

Error: ENOENT: no such file or directory, open '/Users/toddfincannon/Projects/SDEverywhere/models/directdata/x_data.csv'

think this is clear enough that we don't need a special error message.

[chrispcampbell]

Looks good to me, thanks. I'll merge this into the other 81 branch first, and then I'll merge it all together into develop.