Add base64 encoding selector to new file UI so you can add image to repo

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/generic/files.scss

@@ -45,7 +45,7 @@
       text-align: center;
       img {
         padding: 100px;
-        max-width: 300px;
+        max-width: 50%;
       }
     }
 

app/views/projects/new_tree/show.html.haml

@@ -14,6 +14,12 @@
             on
             %span= @ref
 
+    .form-group.commit_message-group
+      = label_tag :encoding, class: "control-label" do
+        Encoding
+      .col-sm-10
+        = select_tag :encoding, options_for_select([ "base64", "text" ], "text"), class: 'form-control'
+
     .form-group.commit_message-group
       = label_tag 'commit_message', class: "control-label" do
         Commit message