Add missing YAML CPAN dependency
Created by: nicklangridge
Add missing YAML CPAN dependency as required here https://github.com/Ensembl/ensembl-rest/blame/release/97/lib/EnsEMBL/REST/Model/Documentation.pm#L33
Created by: nicklangridge
Add missing YAML CPAN dependency as required here https://github.com/Ensembl/ensembl-rest/blame/release/97/lib/EnsEMBL/REST/Model/Documentation.pm#L33