change project invoice to project estimate

Author: claire-peters

coldfront/core/project/templates/project/project_detail.html

@@ -79,7 +79,7 @@ <h3 class="card-title">
 <div class="html2pdf__page-break"></div>
 <div class="card mb-3">
   <div class="card-header">
-    <h3 class="d-inline"><i class="fas fa-file-invoice-dollar" aria-hidden="true"></i> Project Invoice</h3>
+    <h3 class="d-inline"><i class="fas fa-file-invoice-dollar" aria-hidden="true"></i> Project Estimate</h3>
     <span class="badge badge-secondary">{{allocations.count}}</span>
     <div class="float-right">
       {% if project.status.name != 'Archived' and is_allowed_to_update_project %}