Fix Bug 1607 Interface position is not taken into account and

remove vim_gcp from stage-build.sh

This fix provides to attach interfaces to VNF according to the position order
which is defined in the VNFD.

Change-Id: Id0345dc66c3bba8acb0c4c62d9ec21b875c4af72
Signed-off-by: aticig <gulsum.atici@canonical.com>