[864][cygnus][contributing_guidelines.md] Update according to latests changes in RPM and docker
[864][cygnus][contributing_guidelines.md] Update according to latests changes in RPM and docker

telefonicaid/fiware-cygnus,Fiware/data.Cygnus,telefonicaid/fiware-cygnus,Fiware/context.Cygnus,telefonicaid/fiware-cygnus,telefonicaid/fiware-cygnus,Fiware/context.Cygnus,Fiware/data.Cygnus,Fiware/context.Cygnus,Fiware/context.Cygnus,Fiware/data.Cygnus