Provide a clear message if the default option is not specified

This change handles the case when "default: true" is not provided
for some option in the YAML file.

Now, in this scenario, a clear "YAMLProcessingError" is raised,
containing detailed and understandable information about the
misconfiguration.

Added pytests for the following scenarios:
-- YAML parameter does not contain a "default: true" variant
(negative case)
-- YAML parameter contains a "default: true" variant (positive case)

Also, the unit test "test_config.py" was updated because
"default: true" is required for all parameters in the YAML
configuration.

Signed-off-by: Mykhailo Androsiuk <[email protected]>
Reviewed-by: Volodymyr Babchuk <[email protected]>

moulin: bump version to 0.26

There is a new feature for "rouge" was added. Let's bump moulin
version.

Signed-off-by: Volodymyr Babchuk <[email protected]>

moulin: bump version to 0.25

There is hotfix for one of our dependencies, namely gpt-image v0.9.0
added. So we need to bump moulin version.

Signed-off-by: Volodymyr Babchuk <[email protected]>
Reviewed-by: Ruslan Shymkevych <[email protected]>
Tested-by: Mykhailo Androsiuk <[email protected]>

moulin: bump version to 0.24

There is a new "http" fetcher added. Bump up moulin version, to moulin
configs can use "min_version" to be sure that http fetcher is present.

Signed-off-by: Volodymyr Babchuk <[email protected]>

moulin: bump version to 0.23

There were some updates to repo and git fetcher so bump version
and make a new release.

Signed-off-by: Volodymyr Babchuk <[email protected]>

moulin: bump version to 0.21

Increase version after several bug fixes

Signed-off-by: Mykhailo Androsiuk <[email protected]>
Reviewed-by: Volodymyr Babchuk <[email protected]>