some binary ruby are not detected

[witchcraze]

What happened:

some binary ruby are not detected

What you expected to happen:

All binary ruby are detected

Steps to reproduce the issue:

$ syft -q ruby:2.1 | grep ruby
rubygems-update               2.6.12
$
$ docker run -it --rm ruby:2.1 ruby -v
ruby 2.1.10p492 (2016-04-01 revision 54464) [x86_64-linux]

Anything else we need to know?:

[0-9]\.[0-9]\.[0-9] will not match 2.1.10 ...