V2 of the configuration file (#4355)

* Add tests for formats

* Fix tests

* Fix test

* Add tests for conda

* Add tests for build

* Fix test

* Use new interface

* Add tests for python

* Add tests for sphinx

* Add tests for mkdocs

* Add tests for submodules

* Fix tests

* Add tests for `install_project` default

* Add tests for formats default

* Add tests for use_system_packages default

* Add tests for requirements_file default

* Fix tests

* Fix tests

* Tests for docker_image default

* Allow strings and numbers in python.version

* Test stable image

* Fix tests

* Add more validators

* Validate formats and conda

* Implement build

* Fix tests

* More strict validation for lists

* Add python validation

* Fix tests

* Implement validate_python

* Fix tests

* Implements mkdocs

* Fix tests

* Implement validate_submodules

* Linter

* Update submodule

* Validates doc types

* Docstrings

* Update submodule

* Add configurations for new docker images

* Skip test

* Linter

* Rename BuildConfig -> BuildConfigV1

* Add version class selector

* Merge the config_path fro db

* Check for exception

* Refactor

* Update python supported versions

* Remove valid_python_versions

* Fix python key

* Condense block

* Formatting

* Autocommit

* Autocommit

* Autocommit

* Ignore pylint warning

* Fix tests

Some defaults (vaues from the db) are ignored.

* Ignore some values from the db

* Remove unused keys from v1

This ones have a replace in v2

* Add feature flag for configuration file (v2)

* Include sphinx.builder to schema

* Add tests for sphinx.builder key and doctype config property

* Fix tests

* Check for sphinx.builder

* Update test

* Pass doctype to defaults

* Rename sphinx builder option to html

Author: stsewd