DRY up the testing for package source type checks. Refs #18
Update docs, news, and version.
Fix error in extracting archive versions

Version number was not being properly extracted from the archive.

Archive URL was not updated with suffix based on type.

Force archive to be installed from source

CRAN archives do not have binaries, just source.

Fixed tests

Tests were not checking extension of source from root but from archive
Archive versions have tar.gz extension