Use monospace font for commit SHA in branch list

app/views/projects/branches/_commit.html.haml

 .branch-commit
-  = link_to commit.short_id, namespace_project_commit_path(project.namespace, project, commit), class: "commit-id"
+  = link_to commit.short_id, namespace_project_commit_path(project.namespace, project, commit), class: "commit-id monospace"
   ·
   %span.str-truncated
     = link_to_gfm commit.title, namespace_project_commit_path(project.namespace, project, commit.id), class: "commit-row-message"

app/views/projects/tree/_tree_content.html.haml

@@ -12,7 +12,7 @@
               %i.fa.fa-angle-right
                
               %small.light
-                = link_to @commit.short_id, namespace_project_commit_path(@project.namespace, @project, @commit)
+                = link_to @commit.short_id, namespace_project_commit_path(@project.namespace, @project, @commit), class: "monospace"
                 –
                 = truncate(@commit.title, length: 50)
             = link_to 'History', namespace_project_commits_path(@project.namespace, @project, @id), class: 'pull-right'