## Changes
The pattern `errors.Is(err, fs.ErrNotExist)` is common to check for an
error type.
Errors can implement `Is(error) bool` with a custom equivalence checker.
## Tests
New asserts all pass in the integration test.
Adds a DBFS implementation of the `filer.Filer` interface.
The integration tests are reused between the workspace filesystem and
DBFS implementations to ensure identical behavior.
## Changes
Rename all instances of "bricks" to "databricks".
## Tests
* Confirmed the goreleaser build works, uses the correct new binary
name, and produces the right archives.
* Help output is confirmed to be correct.
* Output of `git grep -w bricks` is minimal with a couple changes
remaining for after the repository rename.
shreyas-goenka
Pieter Noordhuis