* Add support for variables in bundle config. Introduces 4 ways of setting variable values, which in decreasing order of priority are: ([#383](https://github.com/databricks/cli/pull/383))([#359](https://github.com/databricks/cli/pull/359)).
1. Command line flag. For example: `--var="foo=bar"`
2. Environment variable. eg: BUNDLE_VAR_foo=bar
3. Default value as defined in the applicable environments block
4. Default value defined in variable definition
* Make the git details bundle config block optional ([#372](https://github.com/databricks/cli/pull/372)).
* Fix api post integration tests ([#371](https://github.com/databricks/cli/pull/371)).
* Fix table of content by removing not required top-level item ([#366](https://github.com/databricks/cli/pull/366)).
* Fix printing the tasks in job output in DAG execution order ([#377](https://github.com/databricks/cli/pull/377)).
* Improved error message when 'bricks bundle run' is executed before 'bricks bundle deploy' ([#378](https://github.com/databricks/cli/pull/378)).