Hardening/135

Implements the issue https://github.com/telefonicaid/fiware-connectors/issues/135

In addition to the `doc/operation/cygnus_01_to_0.*_migration.md` documents, the translation scripts have been modified in order a not sudoer user may run them.

Minor changes have been made in the translation scripts README and in the `doc/operation/ngsi2cosmos_migration.md` document, which references the translation docs.
Maybe we should include (in the index where all Cygnus 0.X to 0.Y are referenced) a note about:

"Cytnus 0.2 to 0.3 (or higher) script has not been develop so far given it is not a relevant migration path so far. In the case you have Cygnus 0.2 and wants to upgrade to 0.3 (or higher) please contact us".

I think this is a smart way of filling the gap without extra effort. What do you think?