Move spec/rubyspec to spec/ruby for consistency

* Other ruby implementations use the spec/ruby directory.
  [Misc #13792] [ruby-core:82287]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59979 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/ruby/library/matrix/rank_spec.rb

@@ -0,0 +1,19 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require 'matrix'
+
+describe "Matrix#rank" do
+  it "returns the rank of the Matrix" do
+    Matrix[ [7,6], [3,9] ].rank.should == 2
+  end
+
+  it "doesn't loop forever" do
+    Matrix[ [1,2,3], [4,5,6], [7,8,9] ].rank.should == 2
+    Matrix[ [1, 2, 0, 3], [1, -2, 3, 0], [0, 0, 4, 8], [2, 4, 0, 6] ].rank.
+    should == 3
+  end
+
+  it "works for some easy rectangular matrices" do
+    Matrix[[0,0],[0,0],[1,0]].rank.should == 1
+    Matrix[[0,1],[0,0],[1,0]].rank.should == 2
+  end
+end