Merge pull request #162 from Mottie/master

Add "btn" class to match new GitHub styling

src/template.html

@@ -16,7 +16,7 @@
             <input name="token" type="text" placeholder="Paste access token here" autocomplete="off">
           </div>
           <div>
-            <button type="submit" class="button">Save</button>
+            <button type="submit" class="button btn">Save</button>
             <a href="https://github.com/buunguyen/octotree#github-access-token" target="_blank" tabIndex="-1">Why is this required?</a>
           </div>
           <div class="error"></div>
@@ -70,7 +70,7 @@
             <input type="text" data-store="TABSIZE">
           </div>
           <div>
-            <button type="submit" class="button">Save</button>
+            <button type="submit" class="button btn">Save</button>
           </div>
         </form>
       </div>