Added missing build files for umd format (are being picked up by the .gitignore 'build/' pattern). This resolves #177.

Author: ironikart

Contrib/Build/umd-footer.js

@@ -0,0 +1,3 @@
+    // Expose globals.
+    return _global;
+}));

Contrib/Build/umd-header.js

@@ -0,0 +1,25 @@
+/**
+ * +--------------------------------------------------------------------+
+ * | This HTML_CodeSniffer file is Copyright (c)                        |
+ * | Squiz Pty Ltd (ABN 77 084 670 600)                                 |
+ * +--------------------------------------------------------------------+
+ * | IMPORTANT: Your use of this Software is subject to the terms of    |
+ * | the Licence provided in the file licence.txt. If you cannot find   |
+ * | this file please contact Squiz (www.squiz.com.au) so we may        |
+ * | provide you a copy.                                                |
+ * +--------------------------------------------------------------------+
+ *
+ */
+(function (root, factory) {
+    if (typeof define === 'function' && define.amd) {
+        define(['htmlcs'], factory);
+    } else if (typeof exports === 'object') {
+        module.exports = factory();
+    } else {
+        var exports = factory();
+        for (var prop in exports) {
+            root[prop] = exports[prop];
+        }
+    }
+}(this, function () {
+    var _global = {}