GitLab

* Support variables in base files for configs
Signed-off-by: lizz <lizz@sensetime.com>

* Test json and yaml as well
Signed-off-by: lizz <lizz@sensetime.com>

* Add test for recusive base
Signed-off-by: lizz <lizz@sensetime.com>

* Test misleading values
Signed-off-by: lizz <lizz@sensetime.com>

* Improve comments
Signed-off-by: lizz <lizz@sensetime.com>

* Add doc
Signed-off-by: lizz <lizz@sensetime.com>

* Improve doc
Signed-off-by: lizz <lizz@sensetime.com>

* More tests
Signed-off-by: lizz <lizz@sensetime.com>

* Harder test case
Signed-off-by: lizz <lizz@sensetime.com>

* use BASE_KEY instead of base
Signed-off-by: lizz <lizz@sensetime.com>