Refactor FTP operations to a single function

[fccoelho]

Many of our modules replicate basic ftp file retrieval operations We should remove all the duplication of code by creating a single function for retrieving files through FTP. this function should most likely belong to an ftptools module in the utilities package.

[anapaulagomes]

Is this issue still valid?

[fccoelho]

Thanks for asking. I don't think so. @luabida has done a big refactoring of the FTP interface. @luabida, can we close this one as stale?

[luabida]

Thanks for asking. I don't think so. @luabida has done a big refactoring of the FTP interface. @luabida, can we close this one as stale?

I guess so. This is the only method responsible for accessing the DATASUS ftp server after the refactor, any special error cases should be handled in its try except block. Currently, the purpose of the try block is to close the ftp connection if any error happen