base: PDFTK path discovery
base: PDFTK path discovery

Signed-off-by: Adrian-Tudor Panescu <aa06e21fa1d97d8759797194b769788a4069f9b1@cern.ch>
Reviewed-by: Jiri Kuncar <2bdffcb416fed3002465740d19a053a39918cbe5@cern.ch>

inveniosoftware/invenio-base,inveniosoftware/invenio-base,tiborsimko/invenio-base,tiborsimko/invenio-base