Added redownload option which if set to true will download the file even if the destination file already exists (default is false)
Merge pull request #5 from ucam-cl-dtg/master

Option for forcing re-download of a file which already exists
added support for nocheckcertificate option
fixed wget commandline addition
Merge pull request #6 from akquinet/nocheckcert

added support for nocheckcertificate option
Merge pull request #1 from maestrodev/master

merge upstream/master