add: 3 missing licenses to constants.py

- CC_BY_NC_40, CC_BY_ND_40 and CC_BY_NC_SA_40 was missing
-- ToDo: we might have to update the "VALID_LICENSE_URLS"-list and the "LICENSE_MAPPINGS"-dict (need confirmation beforehand)

converter/constants.py

@@ -4,7 +4,10 @@ class Constants:
     LICENSE_CC_BY_SA_40 = "https://creativecommons.org/licenses/by-sa/4.0/"
     LICENSE_CC_BY_30 = "https://creativecommons.org/licenses/by/3.0/"
     LICENSE_CC_BY_40 = "https://creativecommons.org/licenses/by/4.0/"
+    LICENSE_CC_BY_NC_40 = "https://creativecommons.org/licenses/by-nc/4.0/"
+    LICENSE_CC_BY_ND_40 = "https://creativecommons.org/licenses/by-nd/4.0/"
     LICENSE_CC_BY_NC_SA_30 = "https://creativecommons.org/licenses/by-nc-sa/3.0/"
+    LICENSE_CC_BY_NC_SA_40 = "https://creativecommons.org/licenses/by-nc-sa/4.0/"
     LICENSE_CC_BY_NC_ND_30 = "https://creativecommons.org/licenses/by-nc-nd/3.0/"
     LICENSE_CC_BY_NC_ND_40 = "https://creativecommons.org/licenses/by-nc-nd/4.0/"
     LICENSE_PDM = "https://creativecommons.org/publicdomain/mark/1.0/"