## Changes
Allows to override default value for a variable definition from the
environment block in a bundle config. See bundle.yml for example usage
## Tests
Unit tests
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Co-authored-by: Pieter Noordhuis <pieter.noordhuis@databricks.com>
If the environment is not set through command line argument or
environment variable, the bundle loads either 1) the only environment,
2) the only environment with the default flag set.
This adds:
* Top level "artifacts" configuration key
* Support for notebooks (does language detection and upload)
* Merge of per-environment artifacts (or artifact overrides) into top level
Load a tree of configuration files anchored at `bundle.yml` into the
`config.Root` struct.
All mutations (from setting defaults to merging files) are observable
through the `mutator.Mutator` interface.