Remove the original 'Write' function from the db package and rename the
'WriteMany' function to 'Write' as it can already write one or many Bolt
items to the database.
Also update the test suites and add more coverage in the board package.
Main change:
Add restrictions when adding IDs for cards and statuses. Errors are
returned when an attempt is made to set an ID lower than 1, or an
attempt is made to set an ID that has already been set.
Additional changes:
- Error types in the board packages are now defined in errors.go.
- Small formatting to error messages.
