gnu: ruby-tdiff: Update to 0.3.3-1.b662a604.

* gnu/packages/ruby.scm: Update to 0.3.3-1.b662a604

gnu/packages/ruby.scm

@@ -2878,18 +2878,23 @@ including comments and whitespace.")
     (license license:expat)))
 
 (define-public ruby-tdiff
+  ;; Use a newer than released snapshot so that rspec-2 is not required.
+  (let ((commit "b662a6048f08abc45c1a834e5f34dd1c662935e2"))
     (package
       (name "ruby-tdiff")
-    (version "0.3.3")
+      (version (string-append "0.3.3-1." (string-take commit 8)))
       (source (origin
-              (method url-fetch)
+                (method git-fetch)
-              (uri (rubygems-uri "tdiff" version))
+                (uri (git-reference
+                      (url "https://github.com/postmodern/tdiff.git")
+                      (commit commit)))
+                (file-name (string-append name "-" version "-checkout"))
                 (sha256
                  (base32
-                "0k41jbvn8qq4mgrixnhlk742b971d136i8wpbcv2cczvi22xpc86"))))
+                  "0n3gq8rx49f7ln6zqlshqfg2mgqyy30rsdjlnki5mv307ykc7ad4"))))
       (build-system ruby-build-system)
       (native-inputs
-     `(("ruby-rspec-2" ,ruby-rspec-2)
+       `(("ruby-rspec" ,ruby-rspec)
          ("ruby-yard" ,ruby-yard)
          ("ruby-rubygems-tasks" ,ruby-rubygems-tasks)))
       (synopsis "Calculate the differences between two tree-like structures")
@@ -2897,7 +2902,7 @@ including comments and whitespace.")
        "This library provides functions to calculate the differences between two
 tree-like structures.  It is similar to Ruby's built-in @code{TSort} module.")
       (home-page "https://github.com/postmodern/tdiff")
-    (license license:expat)))
+      (license license:expat))))
 
 (define-public ruby-nokogiri-diff
   (package