add systemd based distros support

Signed-off-by: Vasiliy Tolstov <v.tolstov@selfip.ru>
fix archlinux platform name;

Signed-off-by: Vasiliy Tolstov <v.tolstov@selfip.ru>
Merge pull request #7 from vtolstov/master

add systemd based distros support
Remove 2.0 builds and added gitter
Bump to chefspec 4, guard 2.6 and rubocop 24. Added arch box to test kitchen
LWRP do over
Update docs
Update tests