Replace link with button in author_actions

- modified corresponding spec

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

@@ -7,7 +7,7 @@
                   edit_budget_investment_path(investment.budget, investment),
                   method: :get, class: "button hollow expanded" %>
     <% else %>
-      <%= link_to image_path(investment.image),
+      <%= button_to image_path(investment.image),
                     method: :delete,
                     class: "button hollow alert expanded" do %>
         <span class="icon-image"></span>

spec/system/budgets/investments_spec.rb

@@ -1715,7 +1715,7 @@ describe "Budget Investments" do
         within("aside") do
           expect(page).not_to have_content "Author"
           expect(page).not_to have_link "Edit"
-          expect(page).not_to have_link "Remove image"
+          expect(page).not_to have_button "Remove image"
         end
       end
 
@@ -1728,7 +1728,7 @@ describe "Budget Investments" do
         within("aside") do
           expect(page).to have_content "AUTHOR"
           expect(page).to have_link "Edit"
-          expect(page).not_to have_link "Remove image"
+          expect(page).not_to have_button "Remove image"
         end
       end
 
@@ -1742,7 +1742,7 @@ describe "Budget Investments" do
         within("aside") do
           expect(page).to have_content "AUTHOR"
           expect(page).not_to have_link "Edit"
-          expect(page).to have_link "Remove image"
+          expect(page).to have_button "Remove image"
         end
       end
     end