* fix: Correct flatten function in layers
- Added a test.
- Cache current image, track deletes in `whiteouts` as well as normal adds in `layers`.
- Fix ugly delete behavior of `layerHashCache`.
Delete it when crerating a new snapshot.
- Slight cleanup in `snapshot.go`.
- Format ugly `WalkFS` function.
* fix: Add symbolic link changes to Hasher and CacheHasher
* fix: Better log messages
* fix(ci): Integration tests
* fix(ci): Add `--no-cache` to docker builds
* fix(ci): Pass credentials for error integration test
* np: Missing .gitignore in `hack`
* np: Capitalize every log message
- Correct some linting.
* fix: Key function
- Merge only last layer onto `currentImage`.
* fix: Remove old obsolete `cacheHasher`
This will return a string representaiton of the current filesystem to be
used with caching.
Whenever a file is explictly added (via ADD or COPY), it will be stored
in "added" in the LayeredMap. The file will map to a hash created by
CacheHasher (which doesn't take into account mtime, since that will be
different with every build, making the cache useless)
Key() will returns a sha of the added files which will be used in
determining the overall cache key for a command.