Build against the latest version of yaml (#57)

This is to pull in improvements to the default behavior for multi-line
string literals

nix/yaml.nix

@@ -0,0 +1,28 @@
+{ mkDerivation, aeson, attoparsec, base, base-compat, bytestring
+, conduit, containers, directory, filepath, hspec, HUnit, mockery
+, mtl, raw-strings-qq, resourcet, scientific, stdenv
+, template-haskell, temporary, text, transformers
+, unordered-containers, vector
+}:
+mkDerivation {
+  pname = "yaml";
+  version = "0.10.2.0";
+  sha256 = "4338d8140f4de63252d40838dd8a7802565f2116ce0170b97a09a2f0dd60747a";
+  configureFlags = [ "-f-system-libyaml" ];
+  isLibrary = true;
+  isExecutable = true;
+  libraryHaskellDepends = [
+    aeson attoparsec base bytestring conduit containers directory
+    filepath mtl resourcet scientific template-haskell text
+    transformers unordered-containers vector
+  ];
+  testHaskellDepends = [
+    aeson attoparsec base base-compat bytestring conduit containers
+    directory filepath hspec HUnit mockery mtl raw-strings-qq resourcet
+    scientific template-haskell temporary text transformers
+    unordered-containers vector
+  ];
+  homepage = "https://github.com/snoyberg/yaml#readme";
+  description = "Support for parsing and rendering YAML documents";
+  license = stdenv.lib.licenses.bsd3;
+}