Release Candidate v0.9.3-rc1

• CSCMETAX-477: [ADD] Legacy data catalog to initialdata catalogs. Add array LEGACY_CATALOGS to settings.py, which holds identifiers of catalogs where pid uniqueness or other validation is not checked, except that a SOME value has to be provided.
• CSCMETAX-477: [FIX] Do not resolve datasets from legacy catalogs
• CSCMETAX-477: [ADD] On DELETE requests datasets in legacy catalogs are deleted permanently
• CSCMETAX-477: [FIX] Allow updating pid of datasets in legacy catalogs
• CSCMETAX-386: [ADD] Validation for File API file_characteristics object's file_format and format_version fields.
• CSCMETAX-492: [REF] Change the format of request for getting urnresolved datasets in oai-pmh API: urnresolver set no longer exists. Using only metadataPrefix=oai_dc_urnresolver datasets can be urnresolved. Optionally, set can be provided but its value must be either datasets or datacatalogs. Currently, datacatalogs returns error since its urnresolving hasn't been implemented. Also single records can be urnresolved, but again currently only with datasets. The change in this commit paves the way for enabling urnresolving datacatalogs, which was not possible with the previous code.
• CSCMETAX-61: [ADD] New python dependency versions
• CSCMETAX-492: [REF] Change is_valid_set method name to validate_mdprefix_and_set: it does not return anything, rather if validation is successful, no exception is raised. Update one python deps.
• CSCMETAX-494: [ADD] Extract the first same_as-entry from license reference data into cache. Populate access_rights.license.license field with the same_as value, if user has not provided any value for it and if the same_as value exists. Fix datacite service for cases when there is no access_rights.license.license field. Add more licenses for full ida test data template.
• CSCMETAX-492: [REF] Speed up getting urnresolver metadata
• CSCMETAX-497: [REF] Change preferred_identifier as non-compulsory field in ida and att schemas. Add readOnly flags to some fields in research_dataset object.
• CSCMETAX-61: [REF] Remove items from minimal dataset template that are not required according to the json schema.
• CSCMETAX-61: [REM] Remove playground from travis deploy script
• CSCMETAX-499: [ADD] Logo and publisher home page for ida and att data catalogs
• CSCMETAX-500: [REF] Send the complete/expanded data_catalog json in RabbitMQ catalog record create and update messages
• CSCMETAX-504: [REF] Change ida and att data catalog titles
• CSCMETAX-61: [ADD|FIX] Add missing pas state to api_schemas. Fix json structure
• CSCMETAX-505: [ADD] Common API query parameter ?dryrun=bool