Add gl-button class to the snippets haml views

app/views/shared/snippets/_form.html.haml

@@ -46,11 +46,11 @@
 
       .form-actions
         - if @snippet.new_record?
-          = f.submit 'Create snippet', class: "btn-success btn", data: { qa_selector: 'submit_button' }
+          = f.submit 'Create snippet', class: "btn-success btn gl-button", data: { qa_selector: 'submit_button' }
         - else
-          = f.submit 'Save changes', class: "btn-success btn", data: { qa_selector: 'submit_button' }
+          = f.submit 'Save changes', class: "btn-success btn gl-button", data: { qa_selector: 'submit_button' }
 
         - if @snippet.project_id
-          = link_to "Cancel", project_snippets_path(@project), class: "btn btn-cancel"
+          = link_to "Cancel", project_snippets_path(@project), class: "btn gl-button btn-default"
         - else
-          = link_to "Cancel", snippets_path(@project), class: "btn btn-cancel"
+          = link_to "Cancel", snippets_path(@project), class: "btn gl-button btn-default"

app/views/shared/snippets/_header.html.haml

@@ -31,15 +31,15 @@
     .embed-snippet
       .input-group
         .input-group-prepend
-          %button.btn.btn-svg.embed-toggle.input-group-text{ 'data-toggle': 'dropdown', type: 'button' }
+          %button.btn.gl-button.btn-svg.embed-toggle.input-group-text{ 'data-toggle': 'dropdown', type: 'button' }
             %span.js-embed-action= _("Embed")
             = sprite_icon('angle-down', size: 12, css_class: 'caret-down')
           %ul.dropdown-menu.dropdown-menu-selectable.embed-toggle-list
             %li
-              %button.js-embed-btn.btn.btn-transparent.is-active{ type: 'button' }
+              %button.js-embed-btn.btn.gl-button.btn-default-tertiary.is-active{ type: 'button' }
                 %strong.embed-toggle-list-item= _("Embed")
             %li
-              %button.js-share-btn.btn.btn-transparent{ type: 'button' }
+              %button.js-share-btn.btn.gl-button.btn-default-tertiary{ type: 'button' }
                 %strong.embed-toggle-list-item= _("Share")
         = snippet_embed_input(@snippet)
         .input-group-append