A pipeline that complements missing package data. Downloads aports
repository and all its necessary branches (alpine versions) then
iterates over all alpine packages associated with the pipeline's
project. For each package it copies additional files from the aports
repository into scan target directory then downloads and extract all
the source archives, performs a scan and saves it's output to package's
database entry.

Signed-off-by: Mateusz Perc <m.perc@samsung.com>

Added new tests for functions:
 -download_or_checkout_aports
 -get_unscanned_packages_from_db
 -prepare_scan_dir
 -extract_summary_fields

Signed-off-by: Mateusz Perc <m.perc@samsung.com>