Get the default target from RUBY env var if set.
Get the default target from RUBY env var if set.

mkb/mspec,MagLev/mspec,ryoqun/mspec,timfel/mspec,opal/mspec,rdp/mspec,kachick/mspec,mrkn/mspec,elia/mspec,rubinius/mspec,MagLev/mspec,iainbeeston/mspec,Gibheer/mspec,ruby/mspec,voxik/mspec,Zoxc/mspec,btakita/mspec,eregon/mspec,shugo/mspec,ruby/mspec,nobu/mspec,yugui/mspec,alex/mspec,kachick/mspec,ryoqun/mspec,iainbeeston/mspec,shirosaki/mspec,opal/mspec,jflam/mspec