Reformat case statement.

Reformat case statement to prevent a warning about an exported variable
from the case statement.
Remove commented code.

Remove commented code.
Fix single value tuple.

Don’t use a single value tuple; use jut the atom alone.
Catch exceptions.

Catch exceptions generated when the node responsible for the request is
unavailable, and return the error status.
Add logging.

Add additional logging and remove errors and warnings about unexpected
variables.
Fix return values.

Read/write can’t handle a singular error atom as a response; they
require a tuple to be returned.
Update test.

Update test to use the new API and error codes.