## Changes
* Add support for using `databricks.yml` as config file. If
`databricks.yml` is not found then falling back to `bundle.yml` for
backwards compatibility.
* Add support for `.yaml` extension.
* Give an error when more than one config file is found
## Tests
* added unit test
* manual testing the different cases
---------
Co-authored-by: Pieter Noordhuis <pieter.noordhuis@databricks.com>
## Changes
Fixed error reporting when included invalid files in include section
Case 1. When the file to include is invalid, throw an error
Case 2. When the file is loaded but the schema is wrong, indicate which
file is failed to load
## Tests
With non-existent notexists.yml
```
databricks bundle deploy
Error: notexists.yml defined in 'include' section does not match any files
```
With malformed notexists.yml
```
databricks bundle deploy
Error: failed to load /Users/andrew.nester/dabs/wheel/notexists.yml: error unmarshaling JSON: json: cannot unmarshal string into Go value of type config.Root
```