[spec] Add Real.rand to spec, as it was already in the spectests and Rakudo.  Change term:<rand> description to refer to it.
[spec] Add Real.rand to spec, as it was already in the spectests and Rakudo.  Change term:<rand> description to refer to it.

git-svn-id: 53605643c415f7495558be95614cf14171f1db78@31727 c213334d-75ef-0310-aa23-eaa082d1ae64

tokuhirom/specs,perl6/specs,tokuhirom/specs,prammer/specs,prammer/specs,perl6/specs,prammer/specs,tokuhirom/specs