springer_crawler: adds new module

* to crawl from Springer web pages.

Signed-off by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
ftp_utils: adds a module to handle ftp downloads.

Signed-off by: Georgios Papoutsakis<georgios.papoutsakis@cern.ch>
Merge pull request #24 from GiorgosPa/ftp_utils

ftp_utils: adds a module to handle ftp downloads.
Merge pull request #22 from GiorgosPa/springer

springer_crawler: adds new module