Merge pull request #1 from yannrouillard/blob-split

Post process elfdump data retrieved from the database to transform List into namedtuple
Unit tests work in progress.
pkgdb: Updated deps in the README
Make testing work on 2.7 (unittest2)
pkgdb: Unit test fixes
checkpkg: ALLOWED_VERSION_DEPENDENCIES fix

If an entry is missing from ALLOWED_VERSION_DEPENDENCIES, do not crash but skip
the check and display an error message instead.
update testdata to remove elf_callbacks field and transform symbol dict into list format