Add edit_image and update_image action to budget/investments controller.

app/views/budgets/investments/_image_form.html.erb

@@ -0,0 +1,29 @@
+<%= form_for([@investment.budget, @investment], url: update_image_budget_investment_path(@investment.budget, @investment), multipart: true, method: :put) do |f| %>
+  <%= render 'shared/errors', resource: @investment %>
+
+  <div class="row">
+
+    <div class="small-12 column">
+      <span class="note-marked">
+        <%= t("budgets.investments.edit_image.note", title: @investment.title) %></p>
+      </span>
+    </div>
+
+    <div class="small-12 column">
+      <%= image_tag @investment.image.url(:large) %>
+    </div>
+
+    <div class="small-12 column">
+      <%= f.file_field :image, accept: 'image/jpeg' %>
+    </div>
+
+    <div class="small-12 column">
+      <%= f.label :image_title, t("budgets.investments.edit_image.form.image_title") %>
+      <%= f.text_field :image_title, placeholder: t("budgets.investments.edit_image.form.image_title"), label: false %>
+    </div>
+
+    <div class="actions small-12 column">
+      <%= f.submit(class: "button", value: t("budgets.investments.edit_image.form.submit_button")) %>
+    </div>
+  </div>
+<% end %>

app/views/budgets/investments/_investment_show.html.erb

@@ -10,6 +10,12 @@
                     class: 'button hollow float-right' %>
       <% end %>
 
+      <% if author_of?(investment, current_user) %>
+        <%= link_to t("budgets.investments.show.edit_image"),
+                    edit_image_budget_investment_path(investment.budget, investment),
+                    class: 'button hollow float-right' %>
+      <% end %>
+
       <h1><%= investment.title %></h1>
 
       <div class="budget-investment-info">

app/views/budgets/investments/edit_image.html.erb

@@ -0,0 +1,10 @@
+<div class="budget-investment-image-edit row">
+
+  <div class="small-12 column">
+    <%= render "shared/back_link" %>
+
+    <h1><%= t("budgets.investments.edit_image.title") %></h1>
+
+    <%= render "image_form" %>
+  </div>
+</div>