installation: introduce version

* Introduces version as implemented on Invenio-demosite.

* Adds Invenio dependency.

Co-authored-by: Javier Martin Montull <javier.martin.montull@cern.ch>
Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
fabfile: add preliminary fabfile for deploys

Co-authored-by: Javier Martin Montull <javier.martin.montull@cern.ch>
Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>