Fix error for client-side parser by improving regex

For the client parser, when the first element of the HTML string
has attributes, the regex will improperly capture everything and
make the tag name invalid.

The fix is to ensure only the tag name is matched and whitespace
is trimmed.

Fixes #23

Author: remarkablemark

lib/html-to-dom-client.js

@@ -102,13 +102,14 @@ function formatDOM(nodes, parentNode) {
  * @return {Object}      - The DOM nodes.
  */
 function htmlToDOMClient(html) {
-    var match = typeof html === 'string' ? html.match(/<(.+?)>/) : null;
+    // from `<p>` or `<p style="">` get `p`
+    var match = typeof html === 'string' ? html.match(/<(.+?)[>\s]/) : null;
     var tagName;
     var parentNode;
     var nodes;
 
     if (match && typeof match[1] === 'string') {
-        tagName = match[1].toLowerCase();
+        tagName = match[1].trim().toLowerCase();
     }
 
     // `DOMParser` can parse full HTML