(Maint) Fix interpreter lines

(Maint) Fix interpreter lines

This time around I actually know why I'm doing this thanks to the
reminder from Nick Lewis.

Ruby will replace itself in memory with the executable listed in the
interpreter line if the string "ruby" is not in there.

Since /usr/bin/env rspec doesn't contain the substring "ruby", you can't
actually run ruby -W1 or whatever on the file.

This patch fixes the problem by making sure "ruby" is present,
preventing ruby from replacing itself in memory.