robotupload: kill the content-length

* Removes the content-length parameter from headers when sending
  robotuploads as it can cause problems when uploading.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
config: remove literature_simple

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
fabfile: new tasks and config updates

* Adds new tasks to conveniently refresh configuration and core
  Invenio package.

* Updates prod configuration.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>