libyaml: minor update 0.1.4 -> .5

The CVE patches are in the release now.

pkgs/development/libraries/libyaml/default.nix

@@ -1,19 +1,18 @@
-{stdenv, fetchurl}:
-
+{ stdenv, fetchurl }:
+let
+  version = "0.1.5";
+in
 stdenv.mkDerivation {
-  name = "libyaml-0.1.4";
+  name = "libyaml-${version}";
 
   src = fetchurl {
-    url = http://pyyaml.org/download/libyaml/yaml-0.1.4.tar.gz;
-    sha256 = "0dvavrhxjrjfxgdgysxqfpdy08lpg3m9i8vxjyvdkcjsmra1by3v";
+    url = "http://pyyaml.org/download/libyaml/yaml-${version}.tar.gz";
+    sha256 = "1vrv5ly58bkmcyc049ad180f2m8iav6l9h3v8l2fqdmrny7yx1zs";
   };
 
-  # Downloaded on 2014-02-01 from https://bugzilla.redhat.com/show_bug.cgi?id=1033990
-  patches = [ ./cve-2013-6393_a.patch ./cve-2013-6393_b.patch ./cve-2013-6393_c.patch ];
-
-  meta = {
+  meta = with stdenv.lib; {
     homepage = http://pyyaml.org/;
     description = "A YAML 1.1 parser and emitter written in C";
-    license = "free";
+    license = licenses.mit;
   };
 }